Difference between global prefilter and postfilter ?

gorby

Hello commoonity 🙂

I can’t find any information about the differences between two types of filters in admin UI.

global prefilter
global postfilter

What are their purpose ?
When are they triggered exactly ?
Why use them instead of the personal filters in SOGo / Roundcube ?

Thanks,

–
Léo.

DarkMatter

Disclaimer: I am new to mailcow, so I will only post what I have learnt so far…

Global Prefilter Purpose:
Acts before any other filtering (e.g., Rspamd, Sieve, or SOGo filters). Used for blocking or rejecting emails early (spam, malware, or known bad senders). It is triggered before Rspamd and any per-user filtering (SOGo/Sieve). Runs at the SMTP level (during email reception).
Global Postfilter Purpose:
Acts after Rspamd and other checks but before delivery to the user’s mailbox. Used for final adjustments (modifying headers, applying additional rules after spam scoring). It is triggered after Rspamd processing but before SOGo/Sieve filters. Runs just before the email is handed to the mailbox.
Personal VS Global
Better performance and global scope (instead of local scope of the personal filters)

gorby

Hey @DarkMatter, thanks for the answer, this is crystal clear, thank you.
Out of curiosity, where did you find such information ? I couldn’t find anything in the mailcow documentation.

DarkMatter

@gorby hi! The information I provided above is a mixture of personal research and AI responses. Please note that not all AI responses are 100% correct. So, research before you apply any suggestions ;-)

gorby

Hey there,
Thanks for the clarification. I didn’t think about asking AI on this one, but the research I made before asking here didn’t provide me with any satisfying result…

Also I saw that @esackbauer did like your post, so if something would have been incorrect, I’m sure he would have tell us. That’s why I’ve selected your answer as the best answer.

–
Léo.