On Wed, 15 Aug 2012, Sergio wrote:
Hello all,
wondering if there could be a rule where the email that is delivered from the
server could be checked the FROM that the domain exist on the server, Is it
possible?
What I am looking is to block any email that is send from my server that is not
using any of the domain accounts that belongs to that server.
Thank you in advance.
Best Regards,
Sergio Cabrera
That sort of check is best done at the SMTP-server (MTA) level. How is SA
to know who are the valid users on your system (including aliases,
forwards, etc).
Your SMTP server must know who your valid recipients are so it can reject
unknown users and deliver the valid ones. So just apply the same kind of
check to the From address (IE if domain === us, check to make sure user ==
ours, else SMTP-REJECT). Details are MTA specific, but most have some kind
of built in check for doing this sort of thing.
The thing which SA can be used for is to hit forgery spam. IE if the
'From' domain is ours, and the sending host isn't one we bless, hit it.
(If you have valid SPF records this is trivially easy to do).
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Dave Funk University of Iowa
<dbfunk (at) engineering.uiowa.edu> College of Engineering
319/335-5751 FAX: 319/384-0549 1256 Seamans Center
Sys_admin/Postmaster/cell_admin Iowa City, IA 52242-1527
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