Question System account sending email through smpt relay but no configuration present

[maratn]

Server operating system version

Almalinux 8.10

Plesk version and microupdate number

18.0.70 Update #2

Hi All,


Until recently we used an external smtp relay for outbound email from the server. This was configured in /etc/postfix/main.cf and nowhere else as far as we can discern. We have marked out the relevant config in the main.cf file and have restarted postfix. All user accounts now send out email using built in smpt functionality but any email sent from the system such as memory usage notifications are still being sent out using the external relay. We can no longer find any configuration relevant to this on the system.

No smarthost has been configured in the email server settings and MSMTP has not been installed.

Things we've tried:

- switching to a different relay.
- switching from postfix to qmail and back again.
- changing the address notifications are sent from

Sadly none of the above worked and email from the system account is still being sent out using the originally configured relay. We've now simply blocked traffic towards the ip of the relay to prevent system emails being sent through it but this is hardly a permanent solution.

Any help would be much appreciated.

 

[Kaspar]

Switching to Qmail does not delete any of the postfix configuration files. So any potential custom configuration is left intact when switching back to Postfix.

If I had to guess I would guess that there either is still some custom relay configuration on Postfix, something in header_checks file would be my first guess, or some custom configuration on dovecot/sieve. It might be worth to searching trough the postfix and dovecot directories for the smarthost/relay with the help of grep. Eg grep -rnw '/etc/dovecot/conf.d/' -e 'smtp2go.com' and grep -rnw '/etc/psotfix/' -e 'smtp2go.com'.

 

[maratn]

Switching to Qmail does not delete any of the postfix configuration files. So any potential custom configuration is left intact when switch back to Postfix.

If I had to guess I would guess that there either is still some custom relay configuration some on Postfix, something in header_checks file would be my first guess, or some configuration on dovecot/sieve. It might be worth to searching trough the postfix and dovecot directories for the smarthost/relay with the help of grep. Eg grep -rnw '/etc/dovecot/conf.d/' -e 'smtp2go.com' and grep -rnw '/etc/psotfix/' -e 'smtp2go.com'.

Thanks a lot. The only file that would possibly seem relevant is the transport.db file. Any references to the relay are marked out in other files. We'll try rebuilding it tonight.

 

[maratn]

Switching to Qmail does not delete any of the postfix configuration files. So any potential custom configuration is left intact when switch back to Postfix.

If I had to guess I would guess that there either is still some custom relay configuration some on Postfix, something in header_checks file would be my first guess, or some configuration on dovecot/sieve. It might be worth to searching trough the postfix and dovecot directories for the smarthost/relay with the help of grep. Eg grep -rnw '/etc/dovecot/conf.d/' -e 'smtp2go.com' and grep -rnw '/etc/psotfix/' -e 'smtp2go.com'.

Rebuilding the transport.db file was indeed the solution. Thanks for the help. Much appreciated!