we face the following situation:

1, Customer created a mailbox (aka subfolder) "ABC" and setup a Pigeonhole Sieve script to file the messages into it. So fine, so good. All seemed to work out well.

2. Customer renamed the mailbox to, let's say, "CDE" and did not change the Sieve script accordingly.

3. We noticed this from a ~/.dovecot.sieve.log (after getting a complaint that messages were not arriving properly anymore :-o ):

"

sieve: info: started log at Apr 28 07:41:11.
error: msgid=<433788c81ea044c4ae49cb39a6f673f3@ALB-DC-EXC08.CLPL.INTERN>: failed to store into mailbox 'ABC': Internal error occurred. Refer to server log for more information. [2022-04-28 07:41:10].

"

Does anybody in this list know if all these messages went to /dev/null - or else? If the latter: where/can we restore the messages?

Which "server log" is meant in this error message? 

I couldn't find the information needed by going through https://doc.dovecot.org/configuration_manual/sieve/ but I wonder if all the messages end in digital nirvana if a user sieve script points to non-existing mailboxes?

Thanks for any hint.

Greetings,

C.