A 'do not email' registry could encourage an even greater volume of spam, the Federal Trade Commission concluded Monday, dismissing the plan as "unfeasible".

The FTC's decision comes after a three month inquiry instigated at the behest of Congress. Capitol Hill lawmakers were eager to see whether last year's highly successful 'do not call' telephone registry might also be applied to electronic mail.

But according to the FTC, an antispam registry could founder on technological grounds. The SMPT (Simple Mail Transfer Protocol) technology used to send email doesn't require senders to attach a valid return address -- as demanded by recent legislation -- thereby allowing use of illegal (and untraceable) fake addresses.

Unlike telephony, which allows junk-callers to be identified, current email technology doesn't 'stamp' a sender's address onto a mailing, making its origin hard to trace. Without such authentication of senders' addresses, the FTC warns, spammers might use a registry to verify email addresses resulting in an even greater volume of spam.

FTC chairman Timothy Muris damns spam "as one of the most daunting consumer-protection problems we've ever faced". He groaned: "When it comes to a 'do not email' registry, consumers will be spammed if we do a registry and spammed if we do not."

Muris plans to host an "authentication summit" with industry participants this fall, aiming to agree on a workable standard. Failing this, the FTC may appoint a federal advisory committee, although Muris hastily assured: "I'm not suggesting that the federal government get involved right away."

A number of consumer groups are urging an 'opt-in' scheme as the best legislative solution. This would force e-marketers to provide a legitimate return address that allows recipients to 'unsubscribe'.

Data sourced from: The Wall Street Journal Online; additional content by WARC staff