SMTP problem: before greeting: client sent data

ℹ️ Support
1

Hello,

I have a instance which was running with no big problems until a week ago. The provider changed a bit in their mail server config for spam protection and now starting SMTP connecting (port 465, SSL) is quit directly after greeting.

Debug says “SMTP ERROR: EHLO command failed: 554 SMTP protocol violation”, the system admin of the mail server says in his logs he has a “before greeting: [...] client sent data” entry (IP masked).

He says (as he sees in his logs, without knowing phpList insides) phpList is not working in standard EHLO routine, is not waiting properly for answer to HELO. And he denies disabling his config again (which I understand, spam sent through this servers is a real problem).

I’ve taken a look in source but cannot find any reason for “sent data”, but I’m not into topic and PHP is not my main language.

Anything I can do?

Regards

(phpList running first was 3.3.3, but updated to latest 3.3.7 with same result.)

2

Strange. Presumably you searched the forum for similar cases already?

This behaviour should be handled by the 3rd party phpmailer library which phpList includes, so you could also look for reports by using that as a keyword.

You can also enable more detailed output from phpmailer which may be of use. Search this forum for examples or see https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting#enabling-debug-output