Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 13 Jul 2007 09:57:25 +0200
From:      "Heiko Wundram (Beenic)" <wundram@beenic.net>
To:        freebsd-questions@freebsd.org
Subject:   Re: Transparent email proxy
Message-ID:  <200707130957.25604.wundram@beenic.net>
In-Reply-To: <200707130730.l6D7U6v9086226@banyan.cs.ait.ac.th>
References:  <200707130730.l6D7U6v9086226@banyan.cs.ait.ac.th>

next in thread | previous in thread | raw e-mail | index | archive | help
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=20
sufficiently high client disappointment), especially if you want to support=
=20
TLS over SMTP (which either means a failed certificate for the sending host=
=20
in case you proxy fully), or not check-/controllable by you (in case you pa=
ss=20
encrypted SMTP on directly).

Easiest solution that worked for me: block all outgoing traffic to ports 25=
=20
and 465, and tell your clients to use <yoursmtphost> as their smarthost,=20
which then accepts the mail, scans it, and sends it on properly. This works=
=20
fine for a university of 8000 computers. ;-)

=2D-=20
Heiko Wundram
Product & Application Development
=2D------------------------------------
Office Germany - EXPO PARK HANNOVER
=20
Beenic Networks GmbH
Mail=E4nder Stra=DFe 2
30539 Hannover
=20
=46on        +49 511 / 590 935 - 15
=46ax        +49 511 / 590 935 - 29
Mail       wundram@beenic.net


Beenic Networks GmbH
=2D------------------------------------
Sitz der Gesellschaft: Hannover
Gesch=E4ftsf=FChrer: Jorge Delgado
Registernummer: HRB 61869
Registergericht: Amtsgericht Hannover



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200707130957.25604.wundram>