Hey there,
i have a rather general question on how mailenable filter systems are working. I did not find a sufficient answer so I hope to receive one here.
We set up various filters which are working fine on the server level in case of "content filtering" (like words, phrases, etc.). But I dont quite get how
filtering for added headers are working.
For example, Plesk Windows is using a built-in spamassassin version adding a prefix to the mails. In addition, there is a header line added "X-ME-Spam: High"
(e.g. if a virus is found scoring 1000) which is coming directly from mail enable.
Could you please clarify why these header additions cannot be filtered on the server level ? Each time a message is received on the SMTP connector,
the rules on my server-level filters are not working in respect of the added header information. Are the headers altered AFTER the server level filters
are used ?
Would this mean, that a spam filtering using header information added by Plesk or the "X-ME-Spam:" flag can only be used on post office filters or mailbox filters ?
Thank you very much.
Sincerely,
Benjamin Busch