E-mail is not sent

[handkerchief333]

Steps to reproduce

1. Compose an e-mail with one main recipient and 24 Bcc recipients.
2. Send the e-mail
3. The e-mail gets stuck in the outbox
4. Open the email again in the outbox
5. Send the e-mail again
6. Status message green: Message sent
7. Status message red: Message could not be deleted
8. Message remains in the outbox as before. It does not appear under "sent".

Expected behavior

The e-mail is sent.

Actual behavior

The e-mail is not sent.

You are also unsure whether the e-mail has been sent, even if it does not appear under "Sent". But since the green status message appears first: Message sent.

Mail app version

3.5.4

Mailserver or service

Hostpoint

Operating system

FreeBSD 13.2

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database

MariaDB

Additional info

The exact same e-mail was sent with slightly fewer Bcc addresses. Could the reason be that 24 addresses are too many?

[handkerchief333]

This error appears in the error log after the status message: Message could not be deleted:

[mail] Error: InvalidArgumentException: Server does not support sending internationalized header data. at <<closure>>

 0. /home/www.example.com/web/apps/mail/vendor/bytestream/horde-mail/lib/Horde/Mail/Transport/Smtphorde.php line 143
    Horde_Smtp->send(["Horde_Mail_Rfc822_Address",[],"max"], ["Horde_Mail_Rfc822_List"], null)
 1. /home/www.example.com/web/apps/mail/vendor/bytestream/horde-mime/lib/Horde/Mime/Part.php line 1620
    Horde_Mail_Transport_Smtphorde->send("info@exampl ... h", ["Max Muster < ... "], null)
 2. /home/www.example.com/web/apps/mail/vendor/bytestream/horde-mime/lib/Horde/Mime/Part.php line 1637
    Horde_Mime_Part->send("info@exampl ... h", ["Horde_Mime_Headers"], ["Horde_Mail_Tra ... e], [])
 3. /home/www.example.com/web/apps/mail/vendor/bytestream/horde-mime/lib/Horde/Mime/Mail.php line 479
    Horde_Mime_Part->send("info@exampl ... h", ["Horde_Mime_Headers"], ["Horde_Mail_Tra ... e])
 4. /home/www.example.com/web/apps/mail/lib/Service/MailTransmission.php line 271
    Horde_Mime_Mail->send(["Horde_Mail_Tra ... e], false, false)
 5. /home/www.example.com/web/apps/mail/lib/Service/MailTransmission.php line 343
    OCA\Mail\Service\MailTransmission->sendMessage(["OCA\\Mail\\Model\\NewMessageData"], null, null)
 6. /home/www.example.com/web/apps/mail/lib/Service/OutboxService.php line 142
    OCA\Mail\Service\MailTransmission->sendLocalMessage(["OCA\\Mail\\Account"], ["OCA\\Mail\\Db\\LocalMessage",754])
 7. /home/www.example.com/web/apps/mail/lib/Controller/OutboxController.php line 247
    OCA\Mail\Service\OutboxService->sendMessage(["OCA\\Mail\\Db\\LocalMessage",754], ["OCA\\Mail\\Account"])
 8. /home/www.example.com/web/lib/private/AppFramework/Http/Dispatcher.php line 230
    OCA\Mail\Controller\OutboxController->send(754)
 9. /home/www.example.com/web/lib/private/AppFramework/Http/Dispatcher.php line 137
    OC\AppFramework\Http\Dispatcher->executeController(["OCA\\Mail\\Con ... "], "send")
10. /home/www.example.com/web/lib/private/AppFramework/App.php line 183
    OC\AppFramework\Http\Dispatcher->dispatch(["OCA\\Mail\\Con ... "], "send")
11. /home/www.example.com/web/lib/private/Route/Router.php line 315
    OC\AppFramework\App::main("OCA\\Mail\\Controller\\OutboxController", "send", ["OC\\AppFramewo ... "], ["754","mail.outbox.send"])
12. /home/www.example.com/web/lib/base.php line 1068
    OC\Route\Router->match("/apps/mail/api/outbox/754")
13. /home/www.example.com/web/index.php line 36
    OC::handleRequest()

POST /index.php/apps/mail/api/outbox/754

[handkerchief333]

#8165 an #8166 are similar.

Ok so I assume that a specific e-mail address is triggering this error?

Very important question: Will the message still be sent to the other e-mail addresses of the same e-mail? Not that I accidentally try to send the e-mail from the inbox to the working e-mail addresses again and again.