Hi,
we are using osTicket 1.18.0 (self hosted) and we see a strange behavior with a filter (the only filter we have).
Usually emailed tickets land in our Support department. We set up another email address that immediately forwards to our primary tickets address.
However, I'd like that tickets that are sent to the new address would end up in another department, so I set up a filter that looks at the destination address and eventually sets the correct department for the generated ticket.
Now, what happens is that, if the filter is triggered, the ticket is correctly put in another department, BUT the automatic reply to the requesting user is not sent out.

Looking in the system log, I see two errors:

Mail Fetcher - Excessive errors processing emails for ssl://imaps.aruba.it:993/IMAP (Supporto Bluebiloba ). Please manually check the Fetch Folder () [1/50 - 0/1]
Mailer Error - Unable to email via SMTP: tickets@domain_amended (ssl://smtps.aruba.it:465/SMTP) 5.2.0 Y40Zr4eftDmMNY40ZroOfY - Mittente non consentito / Sender not allowed ( header-from )

I don't know what causes the first error, but the email message is correctly retrieved anyway. Strangely enough, this error occurs only when the filter is triggered.

The second message is apparently the cause of the fact that the requestor does not get the automatic reply. However, the given reason (Sender not allowed) is nonsense, as the sender is the same as the one used when emails do not trigger the filter.

If I disable the filter, everything works correctly.

I do not know how to debug this situation. I tried to find more detailed logs on the server file system, but did not find any. Apache logs do not report any error.

Does anybody have any insights?

Some info on our system:
Versione di osTicket v1.18 (724de45)
Software del server web Apache/2.4.37 (rocky)
Versione di MySQL 10.3.39
Versione di PHP 8.2.12

O.S. is Rocky Linux v8.8

Thank you in advance
Cris