by Kirill Popov and Loren McDonald

If an e-mail address in your list ceases to be valid, you remove it from the list. Simple enough, right? There are more subtle aspects of bounce management that you might not be acutely aware of, however. We hope this column sheds some light on them.

A bounce is a notification that your message, for whatever reason, didn't make it to the recipient. Ideally, these bounces take the form of SMTP (define) codes, defined as a standard in RFC821. Using these codes, ISPs can communicate the reason for the bounce. Not everyone follows this standard, however, and accurate bounce handling may involve some keyword review of the replies.

Regardless of the bounce message's exact wording, there are two types of bounces: hard and soft. Depending on whom you talk to, they might have more technical definitions; but here is the gist of what they mean.

Read the full article on ClickZ: Increase Delivery Rates With Active Bounce Management