==== Required information ====
- iRedMail version: 0.8.4
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): mysql
- Linux/BSD distribution name and version: debian squeeze
- Related log if you're reporting an issue:
====

i just got informed by a customer that emails that are adressed to an alias and then forwarded internally, do not go through spamassassin at all as there are no X-Spam headers.

as i use sieve to filter spam by the X-Spam Header (move spam to the users spam-folder), i was first pretty confused but i here the answer:

- as it has a X-Virus header the mail goes through amavis! (and therefore spamassassin?)
- first check the postfix logs to see if this mail is really marked as spam OR "Passed CLEAN"
- amavis just adds the X-Spam Headers if the score is above the limit defined with $sa_tag_level_deflt . if you want to always get those just lower it in the amavis config file and restart amavisd.

so if customers get spam that was "Passed CLEAN" by amavis, we need to investigate in the spamfiltering itself...
hope this helps someone not getting too confused (as it happened to me)...