What software for mail filtering?

Z8002 · 11-13-2005, 07:12 AM

I'd be glad of any useful suggestions, I want to implement an "intelligent", controllable mail filter to sit between my home LAN and my ISP.

I want a sort of Linux-based censor to look at e-mail coming in to the network.

What I've currently got is a small network of PCs running Windows, one of these uses Turnpike Connect to collect e-mail from POP servers.

Now, the Windows machines all go through a Linux firewall to communicate with the internet via ADSL.

I want to be able to get my POP mail sent to the Linux machine, there to be filtered and either rejected, put into limbo, or made available to the machine running Turnpike.

Here's what I want the filter to do:

1) Get the mail by POP

2) Apply rules to the headers to reject, accept, or further examine...

3) Apply rules to the content to reject or further examine...

4) Check against a list of known contacts to accept or put in limbo

5) Allow manual transfer of mail from limbo to the accept-pile

6) Reject any mail that has been in limbo for (say) 3 days

7) Add outgoing addresses (except rejection notices) from the Turnpike client to the contacts list.

The idea is that any mail from a previously unknown contact cannot get through to the Windows client, but it still stands a chance of being seen by the Linux administrator and then passed through if it is, indeed, legitimate and wanted.

Any e-mail coming from an address that somone on my network has already written to is presumed to be wanted, unless it looks suspicious.

There is so much e-mail software out there that I don't really know where to start. I'd welcome any suggestions. If I'm faced with a choice, I'd prefer something with a script language that I'm going to be able to learn fairly quickly... something C-like for preference.

Any ideas please?

fouldsy · 11-13-2005, 07:33 AM

Maybe something like SpamAssasain - http://spamassassin.apache.org/ ? Used quite extensively, and I've never had any issues with it once it's trained up.

Z8002 · 11-13-2005, 07:47 AM

Thank you fouldsy, I've had a look at the SpamAssasin pages and it seems to be what I want.

I really want to quarrentine suspect mail on the Linux box and this means I need to chose software to collect the mail by POP and then act as a server for the rest of my LAN, once it has passed through Spam Assasin and been deemed "good".

Which software should I choose? I really am a total

as far as this goes. I've barely got my head around MUAs, MTAs and MDAs...