frank at OPENMINDS.BE
Fri Feb 18 12:59:26 GMT 2005
On Fri, Feb 18, 2005 at 10:52:33AM -0300, Roger Jochem wrote:
> Some accounts in my server are used outside the company, via
> notebooks. Because of some reason, all the messages send by these
> users outside the company are marked as spam.
Probably because there are on a dialup dns blacklist...
> The solution I used for that is to put these e-mail accounts in a spam
> whitelist. But now, there are a lot of e-mails that forge e-mails, and
> I receive lots of e-mails of possible "failed virus" with there
> e-mails as senders, and these messages pass the server (becouse they
> are in a whitelist).
We faced the same problem, and fixed it the following way:
- put smtp-auth on a different port than regular smtp (a lot of isp's
filter tcp/25 anyway, so better use tcp/587). Make sure that the
MTA setup on that port ONLY accepts smtp-auth, no regular smtp.
- put a filter/script/... in the MTA config that adds a specific header
on mails received from that MTA-instance
- put custom spamassassin rules that gives a score -20 to mails that
have that specific header.
Openminds bvba www.openminds.be
Tweebruggenstraat 16 - 9000 Gent - Belgium
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