Have strange forward to non existing emails of the old domain
The correct email still receives the mail but also receives the mail for mail delivery failure which is kinda annoying. There are no forwards and I can't figure out why is this happening.
In this example, firstname.lastname@example.org doesn't exist.
@Vladimir You might want to check (via command line) if you have any stale sieve filters left for the mailbox. This might happen if you switched the webmail installation.
How can I check this? Is it possible to give me the commands?
@Vladimir Can you check
/home/yellowtent/boxdata/mail/vmailon the server? There is a directory for each mailbox. If you enter the mailbox, there is a sieve directory. You can just delete the entire directory to remove the rules and then restart the mail server, in case dovecot had cached it.
(You can also do a quick grep on the address in the above directory to see if it's referenced anywhere else).