Postfix recipient_delimiter not working as intended

Hey there,

i tried using the postfix recimpient_delimiter feature using + as a delimiter, but the emails just get rejected.
Then I configured a Email Alias via the web interface but still the emails get rejected.
The alias I created is *[email protected] because it wouldn't let me create *[email protected]
Manually adding *+lukas@lu..... to the /var/lib/mailman/data/aliases files did not work either

Code:

2025-01-29T18:03:44.650630+00:00 ispconfig postfix/smtpd[35714]: NOQUEUE: reject: RCPT from pxmailgw02.neubauer.cloud[91.107.228.149]: 550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in virtual mailbox table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<pxmailgw02.neubauer.cloud>
2025-01-29T18:03:44.673979+00:00 ispconfig postfix/smtpd[35714]: disconnect from pxmailgw02.neubauer.cloud[91.107.228.149] ehlo=2 starttls=1 mail=1 rcpt=0/1 data=0/1 rset=1 quit=1 commands=6/8

Couldn't find anything helpful so far.
Thank you ahead!

 

You have to change the configuration in Dovecot too in a default ISPConfig setup.
You need to add the "recipient_delimiter = +" Option in the Dovecot configuration too.
Make sure to add the configuration changes to the custom-conf files at /usr/local/ispconfig/server/conf-custom/install/ to make them persistent after ISPConfig updates.

I don't know if there is anything that might not work with recipient_delimiter enabled. Could be possible that some rspamd functions not work properly for example.

 

Sorry that I did not mention it. I already added it to the dovecot conf.
But I didn't add it to a custom install file, thats done now.

This is a default install, I didn't change anything yet besides the recipient_delimiter.