MS gateway checking for valid users before delivery

Erick Perez eaperezh at GMAIL.COM
Thu Dec 29 01:44:34 GMT 2005

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Hi, I've never implemented or read about how to setup the following
config, so I wish some ideas can be given by the members of this list.

in the past few days our microsoft exchange server is taking about 25k
to 35k emails per day. All spam, destined in 80% of the cases to
non-existent addresses in our company. So i think is a good time to
give MS a try.

I will use centos 4.2, MS, Postfix (or sendmail, but like postfix),
MySQL,ClamAV and mailwatch to setup the antispam gateway (yes, we do
not have spam protection blame the board of directors and the budget

I got a script in perl that lets me export the smtp addresses of the 4
domains we handle in the exchange server and i want to setup the
centos box to *not* even try to check for spam/virus/etc if the
recipient does not exist and silently discard the email. If the
recipients emails is valid, then do the anti-spam/virus/etc stuff.

the centos box will also have to be a smart relay since my exchange
server will use it to send to the internet and of course the centos
box will smart forward all processed emails to the exchange box.

I have no idea how to setup this in terms of postfix configuration and
MS configuration.

I posted a smilar question to one postfix forum but I think I didn't
explain myself very well.

Comments, suggestions?

Thanks in advance.


Erick Perez
Linux User 376588  (Get counted!!!)
Panama, Republic of Panama

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