[wp-trac] [WordPress Trac] #33972: static use of PHPMailer class results in stale state between calls to wp_mail()

[WordPress Trac]

#33972: static use of PHPMailer class results in stale state between calls to
wp_mail()
-------------------------------------------------+-------------------------
 Reporter:  codebuddy                            |       Owner:  rishabhwp
     Type:  defect (bug)                         |      Status:  assigned
 Priority:  normal                               |   Milestone:  Future
                                                 |  Release
Component:  Mail                                 |     Version:  4.3
 Severity:  critical                             |  Resolution:
 Keywords:  has-test-info good-first-bug has-    |     Focuses:
  patch needs-testing                            |
-------------------------------------------------+-------------------------

Comment (by sajjad67):

 = Success Test Report =

 After applying the latest patch from [PR
 #9417](https://github.com/WordPress/wordpress-develop/pull/9417) it now
 works perfectly. Sending any length of body text goes into inbox.

 == Environment ==

 * **WordPress:** 6.9-alpha-60093-src
 * **PHP:** 8.2.29
 * **Server:** nginx/1.29.1
 * **Database:** MySQL 8.4.6 (mysqlnd 8.2.29)
 * **Browser:** Chrome 139.0.0.0
 * **OS:** Windows 10/11
 * **Theme:** Twenty Twenty-Five 1.3
 * **Plugins Active:**
   * Email Testing 1.0.0 (custom test plugin)
   * Test Reports 1.2.0

 == ✅ Expected Result ==

 * All test emails should be sent successfully, regardless of body length.

 == ✅ Actual Result ==

 * Emails with **any body length** works now.

 {{{
   Return-Path: <from at example.com>
   Received: from localhost (wordpress-develop-php-1.wordpress-
 develop_wpdevnet. [172.18.0.3])
           by eb84c58a3dd4 (Mailpit) with SMTP
           for <test at example.com>; Tue, 9 Sep 2025 16:30:57 +0000 (UTC)
   Date: Tue, 9 Sep 2025 16:30:57 +0000
   To: test at example.com
   From: WordPress <from at example.com>
   Subject: Test Subject
   Message-ID: <ZBdIPJ9HDcyMmsqahX8mHRUc8iLmI7xrEAJwkvWLh8 at localhost>
   X-Mailer: PHPMailer 6.10.0 (https://github.com/PHPMailer/PHPMailer)
   MIME-Version: 1.0
   Content-Type: text/plain; charset=UTF-8

   A
 }}}

 {{{
   Return-Path: <from at example.com>
   Received: from localhost (wordpress-develop-php-1.wordpress-
 develop_wpdevnet. [172.18.0.3])
           by eb84c58a3dd4 (Mailpit) with SMTP
           for <test at example.com>; Tue, 9 Sep 2025 16:31:48 +0000 (UTC)
   Date: Tue, 9 Sep 2025 16:31:48 +0000
   To: test at example.com
   From: WordPress <from at example.com>
   Subject: Test Subject
   Message-ID: <aSKIP0ZJHQ9cGxaGd3XqWlCJ5iWBNl0LiaY84jekTo at localhost>
   X-Mailer: PHPMailer 6.10.0 (https://github.com/PHPMailer/PHPMailer)
   MIME-Version: 1.0
   Content-Type: text/plain; charset=UTF-8
   Content-Transfer-Encoding: quoted-printable

 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
   AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 }}}

 📸 **Screenshot:**
 [[Image(https://img001.prntscr.com/file/img001/lhbTPQolQSqWnFiADL22Xg.png)]]
 [[Image(https://img001.prntscr.com/file/img001/tg0sP5aZSB6BGmXnOjfoig.png)]]

 == Steps to Reproduce ==

 1. Install and activate the provided **Email Testing** plugin.
 2. Navigate to **Tools → Mail Test** in wp-admin.
 3. Click **Send Test Email**.
 4. Observe results:
   * Messages with any body length succeed.

 == Notes ==

 * Issue resolved after applying [PR #9417](https://github.com/WordPress
 /wordpress-develop/pull/9417).

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/33972#comment:27>
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