SMTP Debug doesn't seem to work - No error log

Hello phplist Community,

I installed phplist and so far everything seems fine expect for DKIM missing in our mails.

In order to understand the problem I’m trying to activate SMTP Debug but I can’t get the log to show up on top of the page when sending a test mail in a campain.

Actually I’m not even convinced I configured SMTP right as I can enter wrong data for host / username / password / … without any notable change. Mails are sent anyway. So maybe SMTP isn’t used at all?!

phplist is installed on a subdomain:
The mail itself is registred to the main domain:
The main domain has an DKIM DNS entry and sending mails (from Thunderbird for example) have a DKIM signature.

The SMTP part of config.php is the following:

define(‘PHPMAILERHOST’, ‘this is the host given by our hoster’);
$phpmailer_smtpuser = ‘the username of the mail account’;
$phpmailer_smtppassword = ‘and the password’;

I tried different ports (25,587,465) and ssl instead of tls.
Also tried setting different debug levels (3,4,5) but I can’t see the log.

I guess its just a stupid mistake somewhere but I can’t see it.
Is it possible the logging is deactivated on server level so it doesn’t get shown?

Thanks and best wishes!

@nefla Ensure that the defines have not already been defined earlier in the file.
Otherwise, are you sure that you are editing the correct file? Usually it is in the lists/config directory, file config.php.

This line in config.php has not been used for a long time
What is the background to this problem? Is is a new installation of phplist, or an old installation that used to work but now does not?

Wow, thank you @duncanc!

Its a new installation.
Yes, it is the correct config.php file but I added our own settings at the end of the existing file without realizing that after database settings there was already a line define(‘PHPMAILERHOST’, ‘’);

After deleting that line SMTP was finally used!
Such a simple mistake but I just didn’t see it. Thanks a lot.

Thanks and best wishes!