src/BounceMailHandler/phpmailer-bmh_rules.php ➔ bmhDSNRules()

Complexity

Conditions	143
Paths	> 20000

Size

Total Lines	1065
Code Lines	427

Duplication

Lines	25
Ratio	2.35 %

Code Coverage

Tests	231
CRAP Score	4226.4347

Importance

Changes

0

<?php
function bmhDSNRules($dsn_msg, $dsn_report, $debug_mode = false)
{
  // initialize the result array
  $result = array(
      'email'           => '',
      'bounce_type'     => false,
      'remove'          => 0,
      'rule_cat'        => 'unrecognized',
      'rule_no'         => '0000',
      'status_code'     => '',
      'action'          => '',
      'diagnostic_code' => '',
  );
  $action = false;
  $status_code = false;
  $diag_code = false;

  // ======= parse $dsn_report ======
  // get the recipient email
  if (preg_match('/Original-Recipient: rfc822;(.*)/i', $dsn_report, $match)) {
    $email = trim($match[1], "<> \t\r\n\0\x0B");
    /** @noinspection PhpUsageOfSilenceOperatorInspection */
    $email_arr = @imap_rfc822_parse_adrlist($email, 'default.domain.name');
    if (isset($email_arr[0]->host) && $email_arr[0]->host != '.SYNTAX-ERROR.' && $email_arr[0]->host != 'default.domain.name') {

This code seems to be duplicated across your project.

      $result['email'] = $email_arr[0]->mailbox . '@' . $email_arr[0]->host;
    }
  } elseif (preg_match('/Final-Recipient: rfc822;(.*)/i', $dsn_report, $match)) {
    $email = trim($match[1], "<> \t\r\n\0\x0B");
    /** @noinspection PhpUsageOfSilenceOperatorInspection */
    $email_arr = @imap_rfc822_parse_adrlist($email, 'default.domain.name');
    if (isset($email_arr[0]->host) && $email_arr[0]->host != '.SYNTAX-ERROR.' && $email_arr[0]->host != 'default.domain.name') {

This code seems to be duplicated across your project.

      $result['email'] = $email_arr[0]->mailbox . '@' . $email_arr[0]->host;
    }
  }

  if (preg_match('/Action: (.+)/i', $dsn_report, $match)) {

This code seems to be duplicated across your project.

    $action = strtolower(trim($match[1]));
    $result['action'] = $action;
  }

  if (preg_match("/Status: ([0-9\.]+)/i", $dsn_report, $match)) {

This code seems to be duplicated across your project.

    $status_code = $match[1];
    $result['status_code'] = $status_code;
  }

  // Could be multi-line , if the new line is beginning with SPACE or HTAB
  if (preg_match("/Diagnostic-Code:((?:[^\n]|\n[\t ])+)(?:\n[^\t ]|$)/is", $dsn_report, $match)) {
    $diag_code = $match[1];
  }

  // No Diagnostic-Code in email, use dsn message
  if (empty($diag_code)) {
    $diag_code = $dsn_msg;
  }

  $result['diagnostic_code'] = $diag_code;

  // ======= rules ======

  if (empty($result['email'])) {
    /* email address is empty
     * rule: full
     * sample:   DSN Message only
     * User quota exceeded: SMTP <xxxxx@yourdomain.com>
     */
    if (preg_match("/quota exceed.*<(\S+@\S+\w)>/is", $dsn_msg, $match)) {

This code seems to be duplicated across your project.

      $result['rule_cat'] = 'full';
      $result['rule_no'] = '0161';
      $result['email'] = $match[1];
    }
  } else {
    /* action could be one of them as RFC:1894
     * "failed" / "delayed" / "delivered" / "relayed" / "expanded"
     */
    switch ($action) {
      case 'failed':
        /* rule: full
         * sample:
         *   Diagnostic-Code: X-Postfix; me.domain.com platform: said: 552 5.2.2 Over
         *     quota (in reply to RCPT TO command)
         */
        if (preg_match('/over.*quota/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0105';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 552 Requested mailbox exceeds quota.
         */
        elseif (preg_match('/exceed.*quota/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0129';
        } /* rule: full
         * sample 1:
         *   Diagnostic-Code: smtp;552 5.2.2 This message is larger than the current system limit or the recipient's mailbox is full. Create a shorter message body or remove attachments and try sending it again.
         * sample 2:
         *   Diagnostic-Code: X-Postfix; host mta5.us4.domain.com.int[111.111.111.111] said:
         *     552 recipient storage full, try again later (in reply to RCPT TO command)
         * sample 3:
         *   Diagnostic-Code: X-HERMES; host 127.0.0.1[127.0.0.1] said: 551 bounce as<the
         *     destination mailbox <xxxxx@yourdomain.com> is full> queue as
         *     100.1.ZmxEL.720k.1140313037.xxxxx@yourdomain.com (in reply to end of
         *     DATA command)
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*full/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0145';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 452 Insufficient system storage
         */
        elseif (preg_match('/Insufficient system storage/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0134';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 422 Benutzer hat zuviele Mails auf dem Server
         */
        elseif (preg_match('/Benutzer hat zuviele Mails auf dem Server/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0998';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 422 exceeded storage allocation
         */
        elseif (preg_match('/exceeded storage allocation/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0997';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 422 Mailbox quota usage exceeded
         */
        elseif (preg_match('/Mailbox quota usage exceeded/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0996';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 422 User has exhausted allowed storage space
         */
        elseif (preg_match('/User has exhausted allowed storage space/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0995';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: SMTP; 422 User mailbox exceeds allowed size
         */
        elseif (preg_match('/User mailbox exceeds allowed size/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0994';
        } /* rule: full
         * sample:
         *   Diagnostic-Code: smpt; 552 Account(s) <a@b.c> does not have enough space
         */
        elseif (preg_match("/not.*enough\s+space/i", $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0246';
        } /* rule: full
         * sample 1:
         *   Diagnostic-Code: X-Postfix; cannot append message to destination file
         *     /var/mail/dale.me89g: error writing message: File too large
         * sample 2:
         *   Diagnostic-Code: X-Postfix; cannot access mailbox /var/spool/mail/b8843022 for
         *     user xxxxx. error writing message: File too large
         */
        elseif (preg_match('/File too large/is', $diag_code)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0192';
        } /* rule: oversize
         * sample:
         *   Diagnostic-Code: smtp;552 5.2.2 This message is larger than the current system limit or the recipient's mailbox is full. Create a shorter message body or remove attachments and try sending it again.
         */
        elseif (preg_match('/larger than.*limit/is', $diag_code)) {
          $result['rule_cat'] = 'oversize';
          $result['rule_no'] = '0146';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: X-Notes; User xxxxx (xxxxx@yourdomain.com) not listed in public Name & Address Book
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user)(.*)not(.*)list/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0103';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: smtp; 450 user path no exist
         */
        elseif (preg_match('/user path no exist/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0106';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 Relaying denied.
         * sample 2:
         *   Diagnostic-Code: SMTP; 554 <xxxxx@yourdomain.com>: Relay access denied
         * sample 3:
         *   Diagnostic-Code: SMTP; 550 relaying to <xxxxx@yourdomain.com> prohibited by administrator
         */
        elseif (preg_match('/Relay.*(?:denied|prohibited)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0108';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 554 qq Sorry, no valid recipients (#5.1.3)
         */
        elseif (preg_match('/no.*valid.*(?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0185';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 «Dªk¦a§} - invalid address (#5.5.0)
         * sample 2:
         *   Diagnostic-Code: SMTP; 550 Invalid recipient: <xxxxx@yourdomain.com>
         * sample 3:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>: Invalid User
         */
        elseif (preg_match('/Invalid.*(?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0111';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 554 delivery error: dd Sorry your message to xxxxx@yourdomain.com cannot be delivered. This account has been disabled or discontinued [#102]. - mta173.mail.tpe.domain.com
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*(?:disabled|discontinued)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0114';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 554 delivery error: dd This user doesn't have a domain.com account (www.xxxxx@yourdomain.com) [0] - mta134.mail.tpe.domain.com
         */
        elseif (preg_match("/user doesn't have.*account/is", $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0127';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 5.1.1 unknown or illegal alias: xxxxx@yourdomain.com
         */
        elseif (preg_match('/(?:unknown|illegal).*(?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0128';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 450 mailbox unavailable.
         * sample 2:
         *   Diagnostic-Code: SMTP; 550 5.7.1 Requested action not taken: mailbox not available
         */
        elseif (preg_match("/(?:alias|account|recipient|address|email|mailbox|user).*(?:un|not\s+)available/is", $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0122';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 553 sorry, no mailbox here by that name (#5.7.1)
         */
        elseif (preg_match('/no (?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0123';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 User (xxxxx@yourdomain.com) unknown.
         * sample 2:
         *   Diagnostic-Code: SMTP; 553 5.3.0 <xxxxx@yourdomain.com>... Addressee unknown, relay=[111.111.111.000]
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*unknown/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0125';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 user disabled
         * sample 2:
         *   Diagnostic-Code: SMTP; 452 4.2.1 mailbox temporarily disabled: xxxxx@yourdomain.com
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*disabled/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0133';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>: Recipient address rejected: No such user (xxxxx@yourdomain.com)
         */
        elseif (preg_match('/No such (?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0143';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 MAILBOX NOT FOUND
         * sample 2:
         *   Diagnostic-Code: SMTP; 550 Mailbox ( xxxxx@yourdomain.com ) not found or inactivated
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*NOT FOUND/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0136';
        } /* rule: unknown
         * sample:
         *    Diagnostic-Code: X-Postfix; host m2w-in1.domain.com[111.111.111.000] said: 551
         *    <xxxxx@yourdomain.com> is a deactivated mailbox (in reply to RCPT TO
         *    command)
         */
        elseif (preg_match('/deactivated (?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0138';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com> recipient rejected
         *   ...
         *   <<< 550 <xxxxx@yourdomain.com> recipient rejected
         *   550 5.1.1 xxxxx@yourdomain.com... User unknown
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*reject/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0148';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: smtp; 5.x.0 - Message bounced by administrator  (delivery attempts: 0)
         */
        elseif (preg_match('/bounce.*administrator/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0151';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 <maxqin> is now disabled with MTA service.
         */
        elseif (preg_match('/<.*>.*disabled/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0152';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 551 not our customer
         */
        elseif (preg_match('/not our customer/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0154';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: smtp; 5.1.0 - Unknown address error 540-'Error: Wrong recipients' (delivery attempts: 0)
         */
        elseif (preg_match('/Wrong (?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0159';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: smtp; 5.1.0 - Unknown address error 540-'Error: Wrong recipients' (delivery attempts: 0)
         * sample 2:
         *   Diagnostic-Code: SMTP; 501 #5.1.1 bad address xxxxx@yourdomain.com
         */
        elseif (preg_match('/(?:unknown|bad).*(?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0160';
        } /* rule: unknown
         * sample:
         *   Status: 5.1.1 (bad destination mailbox address)
         */
        elseif (preg_match('/(?:unknown|bad).*(?:alias|account|recipient|address|email|mailbox|user)/is', $status_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '01601';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 Command RCPT User <xxxxx@yourdomain.com> not OK
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*not OK/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0186';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 5.7.1 Access-Denied-XM.SSR-001
         */
        elseif (preg_match('/Access.*Denied/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0189';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 5.1.1 <xxxxx@yourdomain.com>... email address lookup in domain map failed
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*lookup.*fail/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0195';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 User not a member of domain: <xxxxx@yourdomain.com>
         */
        elseif (preg_match('/(?:recipient|address|email|mailbox|user).*not.*member of domain/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0198';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550-"The recipient cannot be verified.  Please check all recipients of this
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*cannot be verified/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0202';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 Unable to relay for xxxxx@yourdomain.com
         */
        elseif (preg_match('/Unable to relay/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0203';
        } /* rule: unknown
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 xxxxx@yourdomain.com:user not exist
         * sample 2:
         *   Diagnostic-Code: SMTP; 550 sorry, that recipient doesn't exist (#5.7.1)
         */
        elseif (preg_match("/(?:alias|account|recipient|address|email|mailbox|user).*(?:n't|not) exist/is", $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0205';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550-I'm sorry but xxxxx@yourdomain.com does not have an account here. I will not
         */
        elseif (preg_match('/not have an account/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0207';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 This account is not allowed...xxxxx@yourdomain.com
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*is not allowed/is', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0220';
        } /* rule: unknown
         * sample:
         *   Diagnostic-Code: X-Notes; Recipient user name info (a@b.c) not unique.  Several matches found in Domino Directory.
         */
        elseif (preg_match('/not unique.\s+Several matches found/i', $diag_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0255';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>: inactive user
         */
        elseif (preg_match('/inactive.*(?:alias|account|recipient|address|email|mailbox|user)/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0135';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 550 xxxxx@yourdomain.com Account Inactive
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*Inactive/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0155';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>: Recipient address rejected: Account closed due to inactivity. No forwarding information is available.
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user) closed due to inactivity/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0170';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>... User account not activated
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user) not activated/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0177';
        } /* rule: inactive
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 User suspended
         * sample 2:
         *   Diagnostic-Code: SMTP; 550 account expired
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*(?:suspend|expire)/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0183';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 553 5.3.0 <xxxxx@yourdomain.com>... Recipient address no longer exists
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*no longer exist/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0184';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 553 VS10-RT Possible forgery or deactivated due to abuse (#5.1.1) 111.111.111.211
         */
        elseif (preg_match('/(?:forgery|abuse)/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0196';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 553 mailbox xxxxx@yourdomain.com is restricted
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*restrict/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0209';
        } /* rule: inactive
         * sample:
         *   Diagnostic-Code: SMTP; 550 <xxxxx@yourdomain.com>: User status is locked.
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*locked/is', $diag_code)) {
          $result['rule_cat'] = 'inactive';
          $result['rule_no'] = '0228';
        } /* rule: user_reject
         * sample:
         *   Diagnostic-Code: SMTP; 553 User refused to receive this mail.
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user) refused/is', $diag_code)) {
          $result['rule_cat'] = 'user_reject';
          $result['rule_no'] = '0156';
        } /* rule: user_reject
         * sample:
         *   Diagnostic-Code: SMTP; 501 xxxxx@yourdomain.com Sender email is not in my domain
         */
        elseif (preg_match('/sender.*not/is', $diag_code)) {
          $result['rule_cat'] = 'user_reject';
          $result['rule_no'] = '0206';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 554 Message refused
         */
        elseif (preg_match('/Message refused/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0175';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 550 5.0.0 <xxxxx@yourdomain.com>... No permit
         */
        elseif (preg_match('/No permit/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0190';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.5.3 - chkuser)
         */
        elseif (preg_match("/domain isn't in.*allowed rcpthost/is", $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0191';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 553 AUTH FAILED - xxxxx@yourdomain.com
         */
        elseif (preg_match('/AUTH FAILED/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0197';
        } /* rule: command_reject
         * sample 1:
         *   Diagnostic-Code: SMTP; 550 relay not permitted
         * sample 2:
         *   Diagnostic-Code: SMTP; 530 5.7.1 Relaying not allowed: xxxxx@yourdomain.com
         */
        elseif (preg_match('/relay.*not.*(?:permit|allow)/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0241';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 550 not local host domain.com, not a gateway
         */
        elseif (preg_match('/not local host/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0204';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 500 Unauthorized relay msg rejected
         */
        elseif (preg_match('/Unauthorized relay/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0215';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 554 Transaction failed
         */
        elseif (preg_match('/Transaction.*fail/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0221';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: smtp;554 5.5.2 Invalid data in message
         */
        elseif (preg_match('/Invalid data/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0223';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 550 Local user only or Authentication mechanism
         */
        elseif (preg_match('/Local user only/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0224';
        } /* rule: command_reject
         * sample:
         *   Diagnostic-Code: SMTP; 550-ds176.domain.com [111.111.111.211] is currently not permitted to
         *   relay through this server. Perhaps you have not logged into the pop/imap
         *   server in the last 30 minutes or do not have SMTP Authentication turned on
         *   in your email client.
         */
        elseif (preg_match('/not.*permit.*to/is', $diag_code)) {
          $result['rule_cat'] = 'command_reject';
          $result['rule_no'] = '0225';
        } /* rule: content_reject
         * sample:
         *   Diagnostic-Code: SMTP; 550 Content reject. FAAAANsG60M9BmDT.1
         */
        elseif (preg_match('/Content reject/is', $diag_code)) {
          $result['rule_cat'] = 'content_reject';
          $result['rule_no'] = '0165';
        } /* rule: content_reject
         * sample:
         *   Diagnostic-Code: SMTP; 552 MessageWall: MIME/REJECT: Invalid structure
         */
        elseif (preg_match("/MIME\/REJECT/is", $diag_code)) {
          $result['rule_cat'] = 'content_reject';
          $result['rule_no'] = '0212';
        } /* rule: content_reject
         * sample:
         *   Diagnostic-Code: smtp; 554 5.6.0 Message with invalid header rejected, id=13462-01 - MIME error: error: UnexpectedBound: part didn't end with expected boundary [in multipart message]; EOSToken: EOF; EOSType: EOF
         */
        elseif (preg_match('/MIME error/is', $diag_code)) {
          $result['rule_cat'] = 'content_reject';
          $result['rule_no'] = '0217';
        } /* rule: content_reject
         * sample:
         *   Diagnostic-Code: SMTP; 553 Mail data refused by AISP, rule [169648].
         */
        elseif (preg_match('/Mail data refused.*AISP/is', $diag_code)) {
          $result['rule_cat'] = 'content_reject';
          $result['rule_no'] = '0218';
        } /* rule: dns_unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 Host unknown
         */
        elseif (preg_match('/Host unknown/is', $diag_code)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0130';
        } /* rule: dns_unknown
         * sample:
         *   Diagnostic-Code: SMTP; 553 Specified domain is not allowed.
         */
        elseif (preg_match('/Specified domain.*not.*allow/is', $diag_code)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0180';
        } /* rule: dns_unknown
         * sample:
         *   Diagnostic-Code: X-Postfix; delivery temporarily suspended: connect to
         *   111.111.11.112[111.111.11.112]: No route to host
         */
        elseif (preg_match('/No route to host/is', $diag_code)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0188';
        } /* rule: dns_unknown
         * sample:
         *   Diagnostic-Code: SMTP; 550 unrouteable address
         */
        elseif (preg_match('/unrouteable address/is', $diag_code)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0208';
        } /* rule: dns_unknown
         * sample:
         *   Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
         *     for name=aaaaaaaaaaa type=A: Host not found
         */
        elseif (preg_match('/Host or domain name not found/is', $diag_code)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0238';
        } /* rule: dns_loop
         * sample:
         *   Diagnostic-Code: X-Postfix; mail for mta.example.com loops back to myself
         */
        elseif (preg_match('/loops back to myself/i', $diag_code)) {
          $result['rule_cat'] = 'dns_loop';
          $result['rule_no'] = '0245';
        } /* rule: defer
         * sample:
         *   Diagnostic-Code: SMTP; 451 System(u) busy, try again later.
         */
        elseif (preg_match('/System.*busy/is', $diag_code)) {
          $result['rule_cat'] = 'defer';
          $result['rule_no'] = '0112';
        } /* rule: defer
         * sample:
         *   Diagnostic-Code: SMTP; 451 mta172.mail.tpe.domain.com Resources temporarily unavailable. Please try again later.  [#4.16.4:70].
         */
        elseif (preg_match('/Resources temporarily unavailable/is', $diag_code)) {
          $result['rule_cat'] = 'defer';
          $result['rule_no'] = '0116';
        } /* rule: antispam, deny ip
         * sample:
         *   Diagnostic-Code: SMTP; 554 sender is rejected: 0,mx20,wKjR5bDrnoM2yNtEZVAkBg==.32467S2
         */
        elseif (preg_match('/sender is rejected/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0101';
        } /* rule: antispam, deny ip
         * sample:
         *   Diagnostic-Code: SMTP; 554 <unknown[111.111.111.000]>: Client host rejected: Access denied
         */
        elseif (preg_match('/Client host rejected/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0102';
        } /* rule: antispam, mismatch ip
         * sample:
         *   Diagnostic-Code: SMTP; 554 Connection refused(mx). MAIL FROM [xxxxx@yourdomain.com] mismatches client IP [111.111.111.000].
         */
        elseif (preg_match('/MAIL FROM(.*)mismatches client IP/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0104';
        } /* rule: antispam, deny ip
         * sample:
         *   Diagnostic-Code: SMTP; 554 Please visit http:// antispam.domain.com/denyip.php?IP=111.111.111.000 (#5.7.1)
         */
        elseif (preg_match('/denyip/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0144';
        } /* rule: antispam, deny ip
         * sample:
         *   Diagnostic-Code: SMTP; 554 Service unavailable; Client host [111.111.111.211] blocked using dynablock.domain.com; Your message could not be delivered due to complaints we received regarding the IP address you're using or your ISP. See http:// blackholes.domain.com/ Error: WS-02
         */
        elseif (preg_match('/client host.*blocked/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0242';
        } /* rule: antispam, reject
         * sample:
         *   Diagnostic-Code: SMTP; 550 Requested action not taken: mail IsCNAPF76kMDARUY.56621S2 is rejected,mx3,BM
         */
        elseif (preg_match('/mail.*reject/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0147';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 552 sorry, the spam message is detected (#5.6.0)
         */
        elseif (preg_match('/spam.*detect/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0162';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 554 5.7.1 Rejected as Spam see: http:// rejected.domain.com/help/spam/rejected.html
         */
        elseif (preg_match('/reject.*spam/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0216';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 553 5.7.1 <xxxxx@yourdomain.com>... SpamTrap=reject mode, dsn=5.7.1, Message blocked by BOX Solutions (www.domain.com) SpamTrap Technology, please contact the domain.com site manager for help: (ctlusr8012).
         */
        elseif (preg_match('/SpamTrap/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0200';
        } /* rule: antispam, mailfrom mismatch
         * sample:
         *   Diagnostic-Code: SMTP; 550 Verify mailfrom failed,blocked
         */
        elseif (preg_match('/Verify mailfrom failed/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0210';
        } /* rule: antispam, mailfrom mismatch
         * sample:
         *   Diagnostic-Code: SMTP; 550 Error: MAIL FROM is mismatched with message header from address!
         */
        elseif (preg_match('/MAIL.*FROM.*mismatch/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0226';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 554 5.7.1 Message scored too high on spam scale.  For help, please quote incident ID 22492290.
         */
        elseif (preg_match('/spam scale/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0211';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 554 5.7.1 reject: Client host bypassing service provider's mail relay: ds176.domain.com
         */
        elseif (preg_match('/Client host bypass/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0229';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 550 sorry, it seems as a junk mail
         */
        elseif (preg_match('/junk mail/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0230';
        } /* rule: antispam
         * sample:
         *   Diagnostic-Code: SMTP; 553-Message filtered. Please see the FAQs section on spam
         */
        elseif (preg_match('/message filtered/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0243';
        } /* rule: antispam, subject filter
         * sample:
         *   Diagnostic-Code: SMTP; 554 5.7.1 The message from (<xxxxx@yourdomain.com>) with the subject of ( *(ca2639) 7|-{%2E* : {2"(%EJ;y} (SBI$#$@<K*:7s1!=l~) matches a profile the Internet community may consider spam. Please revise your message before resending.
         */
        elseif (preg_match('/subject.*consider.*spam/is', $diag_code)) {
          $result['rule_cat'] = 'antispam';
          $result['rule_no'] = '0222';
        } /* rule: internal_error
         * sample:
         *   Diagnostic-Code: SMTP; 451 Temporary local problem - please try later
         */
        elseif (preg_match('/Temporary local problem/is', $diag_code)) {
          $result['rule_cat'] = 'internal_error';
          $result['rule_no'] = '0142';
        } /* rule: internal_error
         * sample:
         *   Diagnostic-Code: SMTP; 553 5.3.5 system config error
         */
        elseif (preg_match('/system config error/is', $diag_code)) {
          $result['rule_cat'] = 'internal_error';
          $result['rule_no'] = '0153';
        } /* rule: delayed
         * sample:
         *   Diagnostic-Code: X-Postfix; delivery temporarily suspended: conversation with
         *   111.111.111.11[111.111.111.11] timed out while sending end of data -- message may be
         *   sent more than once
         */
        elseif (preg_match('/delivery.*suspend/is', $diag_code)) {
          $result['rule_cat'] = 'delayed';
          $result['rule_no'] = '0213';
        }

        // =========== rules based on the dsn_msg ===============

        /* rule: unknown
         * sample:
         *   ----- The following addresses had permanent fatal errors -----
         *   <xxxxx@yourdomain.com>
         *   ----- Transcript of session follows -----
         *   ... while talking to mta1.domain.com.:
         *   >>> DATA
         *   <<< 503 All recipients are invalid
         *   554 5.0.0 Service unavailable
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user)(.*)invalid/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0107';
        } /* rule: unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   xxxxx@yourdomain.com... Deferred: No such file or directory
         */
        elseif (preg_match('/Deferred.*No such.*(?:file|directory)/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0141';
        } /* rule: unknown
         * sample:
         *   Failed to deliver to '<xxxxx@yourdomain.com>'
         *   LOCAL module(account xxxx) reports:
         *   mail receiving disabled
         */
        elseif (preg_match('/mail receiving disabled/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0194';
        } /* rule: unknown
         * sample:
         *   - These recipients of your message have been processed by the mail server:
         *   xxxxx@yourdomain.com; Failed; 5.1.1 (bad destination mailbox address)
         */
        elseif (preg_match('/bad.*(?:alias|account|recipient|address|email|mailbox|user)/i', $status_code)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '02441';
        } /* rule: unknown
         * sample:
         *   - These recipients of your message have been processed by the mail server:
         *   xxxxx@yourdomain.com; Failed; 5.1.1 (bad destination mailbox address)
         */
        elseif (preg_match('/bad.*(?:alias|account|recipient|address|email|mailbox|user)/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0244';
        } /* rule: full
         * sample 1:
         *   This Message was undeliverable due to the following reason:
         *   The user(s) account is temporarily over quota.
         *   <xxxxx@yourdomain.com>
         * sample 2:
         *   Recipient address: xxxxx@yourdomain.com
         *   Reason: Over quota
         */
        elseif (preg_match('/over.*quota/i', $dsn_msg)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0131';
        } /* rule: full
         * sample:
         *   Sorry the recipient quota limit is exceeded.
         *   This message is returned as an error.
         */
        elseif (preg_match('/quota.*exceeded/i', $dsn_msg)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0150';
        } /* rule: full
         * sample:
         *   The user to whom this message was addressed has exceeded the allowed mailbox
         *   quota. Please resend the message at a later time.
         */
        elseif (preg_match("/exceed.*\n?.*quota/i", $dsn_msg)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0187';
        } /* rule: full
         * sample 1:
         *   Failed to deliver to '<xxxxx@yourdomain.com>'
         *   LOCAL module(account xxxxxx) reports:
         *   account is full (quota exceeded)
         * sample 2:
         *   Error in fabiomod_sql_glob_init: no data source specified - database access disabled
         *   [Fri Feb 17 23:29:38 PST 2006] full error for caltsmy:
         *   that member's mailbox is full
         *   550 5.0.0 <xxxxx@yourdomain.com>... Can't create output
         */
        elseif (preg_match('/(?:alias|account|recipient|address|email|mailbox|user).*full/i', $dsn_msg)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0132';
        } /* rule: full
         * sample:
         *   gaosong "(0), ErrMsg=Mailbox space not enough (space limit is 10240KB)
         */
        elseif (preg_match('/space.*not.*enough/i', $dsn_msg)) {
          $result['rule_cat'] = 'full';
          $result['rule_no'] = '0219';
        } /* rule: defer
         * sample 1:
         *   ----- Transcript of session follows -----
         *   xxxxx@yourdomain.com... Deferred: Connection refused by nomail.tpe.domain.com.
         *   Message could not be delivered for 5 days
         *   Message will be deleted from queue
         * sample 2:
         *   451 4.4.1 reply: read error from www.domain.com.
         *   xxxxx@yourdomain.com... Deferred: Connection reset by www.domain.com.
         */
        elseif (preg_match('/Deferred.*Connection (?:refused|reset)/i', $dsn_msg)) {
          $result['rule_cat'] = 'defer';
          $result['rule_no'] = '0115';
        } /* rule: dns_unknown
         * sample:
         *   ----- The following addresses had permanent fatal errors -----
         *   Tan XXXX SSSS <xxxxx@yourdomain..com>
         *   ----- Transcript of session follows -----
         *   553 5.1.2 XXXX SSSS <xxxxx@yourdomain..com>... Invalid host name
         */
        elseif (preg_match('/Invalid host name/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0239';
        } /* rule: dns_unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   xxxxx@yourdomain.com... Deferred: mail.domain.com.: No route to host
         */
        elseif (preg_match('/Deferred.*No route to host/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0240';
        } /* rule: dns_unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   550 5.1.2 xxxxx@yourdomain.com... Host unknown (Name server: .: no data known)
         */
        elseif (preg_match('/Host unknown/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0140';
        } /* rule: dns_unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   451 HOTMAIL.com.tw: Name server timeout
         *   Message could not be delivered for 5 days
         *   Message will be deleted from queue
         */
        elseif (preg_match('/Name server timeout/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0118';
        } /* rule: dns_unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   xxxxx@yourdomain.com... Deferred: Connection timed out with hkfight.com.
         *   Message could not be delivered for 5 days
         *   Message will be deleted from queue
         */
        elseif (preg_match('/Deferred.*Connection.*tim(?:e|ed).*out/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0119';
        } /* rule: dns_unknown
         * sample:
         *   ----- Transcript of session follows -----
         *   xxxxx@yourdomain.com... Deferred: Name server: domain.com.: host name lookup failure
         */
        elseif (preg_match('/Deferred.*host name lookup failure/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_unknown';
          $result['rule_no'] = '0121';
        } /* rule: dns_loop
         * sample:
         *   ----- Transcript of session follows -----
         *   554 5.0.0 MX list for znet.ws. points back to mail01.domain.com
         *   554 5.3.5 Local configuration error
         */
        elseif (preg_match('/MX list.*point.*back/i', $dsn_msg)) {
          $result['rule_cat'] = 'dns_loop';
          $result['rule_no'] = '0199';
        } /* rule: internal_error
         * sample:
         *   ----- Transcript of session follows -----
         *   451 4.0.0 I/O error
         */
        elseif (preg_match("/I\/O error/i", $dsn_msg)) {
          $result['rule_cat'] = 'internal_error';
          $result['rule_no'] = '0120';
        } /* rule: internal_error
         * sample:
         *   Failed to deliver to 'xxxxx@yourdomain.com'
         *   SMTP module(domain domain.com) reports:
         *   connection with mx1.mail.domain.com is broken
         */
        elseif (preg_match('/connection.*broken/i', $dsn_msg)) {
          $result['rule_cat'] = 'internal_error';
          $result['rule_no'] = '0231';
        } /* rule: other
         * sample:
         *   Delivery to the following recipients failed.
         *   xxxxx@yourdomain.com
         */
        elseif (preg_match("/Delivery to the following recipients failed.*\n.*\n.*" . $result['email'] . '/i', $dsn_msg)) {
          $result['rule_cat'] = 'other';
          $result['rule_no'] = '0176';
        }

        // Followings are wind-up rule: must be the last one
        //   many other rules msg end up with "550 5.1.1 ... User unknown"
        //   many other rules msg end up with "554 5.0.0 Service unavailable"

        /* rule: unknown
         * sample 1:
         *   ----- The following addresses had permanent fatal errors -----
         *   <xxxxx@yourdomain.com>
         *   (reason: User unknown)
         * sample 2:
         *   550 5.1.1 xxxxx@yourdomain.com... User unknown
         */
        elseif (preg_match('/(?:User unknown|Unknown user)/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0193';
        } /* rule: unknown
         * sample:
         *   554 5.0.0 Service unavailable
         */
        elseif (preg_match('/Service unavailable/i', $dsn_msg)) {
          $result['rule_cat'] = 'unknown';
          $result['rule_no'] = '0214';
        }
        break;

      case 'delayed':
        $result['rule_cat'] = 'delayed';
        $result['rule_no'] = '0110';
        break;

      case 'delivered':
      case 'relayed':
      case 'expanded': // unhandled cases
        break;

      default:
        break;
    }
  }

  global $rule_categories, $bmh_newline;

Use of global functionality is not recommended; it makes your code harder to test, and less reusable.

  if ($result['rule_no'] == '0000') {
    if ($debug_mode) {
      echo 'email: ' . $result['email'] . $bmh_newline;
      echo 'Action: ' . $action . $bmh_newline;
      echo 'Status: ' . $status_code . $bmh_newline;
      echo 'Diagnostic-Code: ' . $diag_code . $bmh_newline;
      echo "DSN Message:<br />\n" . $dsn_msg . $bmh_newline;
      echo $bmh_newline;
    }
  } else {

This code seems to be duplicated across your project.

    if ($result['bounce_type'] === false) {
      $result['bounce_type'] = $rule_categories[$result['rule_cat']]['bounce_type'];
      $result['remove'] = $rule_categories[$result['rule_cat']]['remove'];
    }
  }

  return $result;
}