Re: Transparent email proxy

On Friday 13 July 2007 09:30:06 Olivier Nicole wrote:
As an ISP, or the person in charge of a large organisation, have you
ever set-up a transparent email redirection: all outgoing email would
be proceeded to an outgoing server in order to check for virus, spam,
whatever.

Don't do this transparently. Only leads to pain and suffering (and
sufficiently high client disappointment), especially if you want to support
TLS over SMTP (which either means a failed certificate for the sending host
in case you proxy fully), or not check-/controllable by you (in case you pass
encrypted SMTP on directly).

Easiest solution that worked for me: block all outgoing traffic to ports 25
and 465, and tell your clients to use <yoursmtphost> as their smarthost,
which then accepts the mail, scans it, and sends it on properly. This works
fine for a university of 8000 computers. ;-)

--
Heiko Wundram
Product & Application Development
-------------------------------------
Office Germany - EXPO PARK HANNOVER

Beenic Networks GmbH
Mailänder Straße 2
30539 Hannover

Fon +49 511 / 590 935 - 15
Fax +49 511 / 590 935 - 29
Mail wundram@xxxxxxxxxx


Beenic Networks GmbH
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Registernummer: HRB 61869
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