Mac Musings

Hotmail Fights Spam (and So Do I)

Daniel Knight - 1999.11.11 -

Although Cnet finds it controversial, I'd like to welcome Microsoft's Hotmail service to the ranks of those using MAPS RBL.

As an email administrator, Mail Abuse Prevention System's (MAPS) Realtime Blackhole List (RBL) is one of my favorite anti-spam tools. It only lists servers known to relay spam after the email administrator has been contacted and doesn't shut down the open relay.

There are several other anti-spam tools. One (ORBS) will blacklist any open relay, whether it's ever been used to relay spam or not. Another blacklists specific dialup addresses known as spam sources.

My current mail server only allows me to use one of these tools. Like Microsoft, I chose MAPS RBL because it doesn't presume a server is guilty by association, as ORBS does. Until they have proof of relayed spam, RBL won't list a site.

Controversial?

As someone whose been dealing with spam since we first set up a company mail server with a connection to the internet, I'm disappointed Cnet labels MAPS RBL controversial. Any email administrator not using some anti-spam tools should be flogged - and MAPS RBL seems to find the right balance between blocking too many servers and not blocking enough.

It has certainly reduced the amount of spam I receive via the two servers I run.

Granted, MAPS RBL does block some legitimate email. Any anti-spam mechanism takes that risk, but at least it only blocks servers tried and found guilty of relaying spam. When I explain this, most users are understanding. Most email administrators will do all they can to stay off the ORBS and RBL lists. It's only those servers that persist in maintaining open relays for any and all email that are blocked by MAPS RBL.

It's an area I and other email administrators have discussed heavily on the SIMS (Stalker Internet Mail Server, a freeware Mac-based internet compatible email server) email list - how do the various blocking lists work, and which best fit our paradigm who should be blocked. In fact, SIMS is being upgraded to allow use of more than one anti-spam service, a move everyone on the list applauds.

Until the government makes spam illegal and spammers comply with anti-spam laws, email administrators will continue using blocking lists, controversial or not.

Further Reading

• Hotmail implements spam filter, Slashdot, 1999.11.09