How do you deal with spam on your mail server?

[Ron]

On the subject, I'd like to requst a mail server specific forum.:)

I just wanted to know from mail server admins, what your stance is
and how you deal with/filter spam at the server level if at all.
What mail servers you use, spam gates you use etc.

I have been using some decent methods like rules/triggers IPsubnet
blocking with whitelisting backend and have found significant progress
but it still isn't enough. I have been considering buying another
server for a spam gate and just wanted some thoughts from others,
maybe I'll find another way.

I am currently running in a Windows enviroment but have considered
RedHat as the secondary server.

[dhigbee]

Spamassassin does pretty good. You do need to tweek it a bit to get the results you want. There are plenty how tos on how to install.

Don

[altp]

Spamassassin.

I don't use it server wide, I let everyone that has an email account set it up themselves using usermin.

It seems to work well. I've gotten, since last sunday 500 spam emails. but i've only seen 3 pf them. 2 of them were in an asian language ...

so, it seems too work really well. But i have very strict rules as well.

[spoon]

I'm also using spamassassin and I'm satisfied with it.

I tried setting it up to work with sendmail's milter interface, but wasn't able to get it working just right and instead decided to make it available for people to use if they wanted to (or ignore if they didn't) by putting it in the procmailrc. There are a couple of alternatives to spamassassin, but I'm blanking on the names right now.

Personally, I don't think the whitelist/blacklist approach is very elegant and there seems to be more than a few occasions where people are unfairly denied access because the blacklists are forced to use such broad bans to catch the really elusive spammers. Filtering it out on a case by case basis seems like the way to go.

Finally, I remember hearing of an approach someone took to setup their mail server to keep a log of known good From addresses. If email came in from an unknown address, the server would reply to the sender and ask them to authenticate before delivering the message. I'm not sure if the source code was ever released, but it might be something else to look into setting up.

[fishfreek]

Im another spamassassin junkie.

I have it setup so each e-mail going thru the SMTP gateway is processed. This includes outbound mail simply because I did not feel like doing the extra work to have outgoing mail go thru some other way.

I use postfix as my e-mail server. When I set spamassisin up I found a great howto linked from their site on how to incorporate it into postfix.

[wunderlin]

I use the blacklists spamcop and spamhaus. It's reduced our spam traffic to a tolerable level, at least for now. I also have a custom MTA filter on Mail Enable that I developed to stop the frequently recurring spams that make it past the blacklists.

[Infopro]

I'm on a cpanel server and I gues I still have to figure this out a bit, but my mail queue gets loaded with crap almost daily.
(spamassasin on)

I just checked it right now, it says..
There are currently 418 messages in the mail queue.
:confused: