[Bug]: SMTP mail sends unrecognized commands

[cobyteskb]

Describe the problem

Hi There,

We tried to configure SMTP mail, but our mailserver won't accept any e-mails due to unrecognized commands (Headers). These are:

• X-Mailer
• MIME-Version

2025-09-10 14:40:40 SMTP call from dnsadmin dropped: too many unrecognized commands (last was "X-Mailer: Poweradmin Mailer")
2025-09-10 14:43:59 SMTP call from dnsadmin dropped: too many unrecognized commands (last was "MIME-Version: 1.0")

These headers are added in lib/Application/Service/MailService.php

poweradmin/lib/Application/Service/MailService.php

Line 494 in 3ee9de7

'X-Mailer' => 'Poweradmin Mailer',

poweradmin/lib/Application/Service/MailService.php

Line 495 in 3ee9de7

'MIME-Version' => '1.0',

When i remove these 2 headers from the above file, the e-mail is send out withoud any issues!

These headers (SMTP commands) are not allowed in the SMTP protocol.

Steps to reproduce

1. Edit file lib/Application/Service/MailService.php
2. Remove header X-Mailer on line 494
3. Remove header MIME-Version on line 495
4. Send mail

Poweradmin version

4.0.1

Database

MySQL

Additional information (optional)

No response

[edmondas]

@cobyteskb Thanks for this report, this sounds interesting. What kind of SMTP server is it, if you don't mind me asking?

For now, the patch release will contain some fixes, but in the master branch (next minor release) the custom SMTP mailer will be replaced with a Symfony component for better compatibility and reliability with SMTP servers.

[cobyteskb]

Thanks for the fix and upcoming change to Symfony mail component, makes sense and feels more solid to me!

We tested 2 mailservers, both running Exim.