Anti-spam services must avoid creating yet more spam

Bagnall: Some spam solutions create even more unwanted email

The myriad anti-spam services available must do better. Many result in as much unwanted mail as they prevent by creating "backscatter", a flood of non-delivery reports associated with all the emails they block.

These are received by other users whose email address has been spoofed by a spammer – generating an additional email for every piece of spam sent.

The right anti-spam service can block the email at the initial connection before the data has been sent, and leave the email itself on the sending server.

A 550 error from the server will let the sender know the email has been rejected.

Applying this policy across thousands of domains receiving millions of spam emails means a significant bandwidth and processing power saving.

Savings made by an email-filtering company doing this means they may move on to offer a better solution that is less prone to denial-of-service attacks.

Email filtering services should block at least 95 per cent of email using connection filtering either from themselves or a partner.

Unnecessary internet traffic costs everyone on some level.

Backscatter is common when companies use in-house software and appliances to deal
with spam.

I believe that this level of connection filtering is only prevalent in a handful of hosted anti-spam solutions.

We think resellers should insist on this when investigating products for their customers.

Ken Bagnall is managing director at the Email Laundry