Archive for the ‘spam’ Category

BarricadeMX: The ultimate spam-fighting app, server-side

September 5, 2007

Hi,

I have tried FSL’s BarricadeMX software at two of my client’s site. This piece of software is a giant step in the battle against spam.

What is it?

It is an SMTP proxy, which does many, many tests during the SMTP transaction in a very efficient way. If one test fails, it rejects the message with a 5xx SMTP reply, so the sender should be notified. Il also implements Greylisting in a more intelligent manner than most current Greylisting implementations.

I installed and configured it for 2 clients which are in a different situation: One is a high-volume, multiple servers setup, and the other is a smaller setup with only 1 scanning server.

On the big setup, it allowed this client to stop the delays they were experiencing and the spam-catching rate is a lot higher. It also simplfied management.

On the smaller setup, I enabled BarricadeMX’s clamd and spamd support. This way, viruses are blocked at the MTA level, and any spam that scores over a defined parameter. In this case, I chose to block anything that gets a spamassassin score over 15.
It is a lot easier to manage than the previous setup (FSL has a yum repository, so updating is very simple). I also got rid of the quarantine, and now every false positive gets notified.

I strongly recommend BarricadeMX to anyone who has a Unix/Linux server on hand. It will eventually even run on Microsoft Exchange!

You can try BarricadeMX for 30 days for free. I suggest you ask for the pricelist at the same time, because once you’ve tried it, you won’t be able to let it go!

Free Pub for LastSpam

April 19, 2007

I strongly recommend this good anti-spam service for anyone who has its own domain: www.lastspam.com

milter-greylist

November 3, 2006

Hi,

A few words on milter-greylist, especially because the new version (3) is now RC6 and looks pretty stable. What are the features of milter-greylist?

  • Per-domain and per-user settings.
  • Friendly networks whitelisting
  • Multi-MX sync (database is replicated many mail servers if needed)
  • SMTP-AUTH support
  • SPF records: can be configured not to impose GreyListing to messages that are SPF-compliant
  • Access lists with DNSbls

This last option is new in version 3. It is very nice: it allows one to configure milter-greylist to impose GreyListing if the source IP is on (configurable) DNS black lists (DNSbls).

I’ve installed it and it decreased the number of messages/day by about 60%. I only had to whitelist one server.

New source of DNSBL and ClamAV unofficial DBs

September 8, 2006

http://www.msrbl.com/

Looks promising.

Sendmail milters from SnertSoft

September 2, 2006

This is just a quick post to encourage people to try SnertSoft’s excellent anti-spam milters. If you’re running a spam-filtering gateway, you may want to try milter-ahead. It checks at the backend mail server if the user exists before accepting the message.

Milter-sender is also very interesting, it checks for the existence of the sender’s e-mail before accepting the message.

Milter-link checks for URL in message bodies againsts URI blacklists. And this one is free! (most are).

All the milters’ descriptions are here.

Anthony, the author, is very kind and offers good support. Have a look at his website. There are many other milters that may help you reduce the load on your spam-filtering system and reduce the number of spams that make it to your user’s mailbox!