This means that some hard bounces, such as bad addresses, should be removed immediately if you’re confident in the accuracy of the ISP reporting the failure. But it also means that all bounces should be subject to removal at some point if they continue to bounce for the same reason.
So if you can’t address the underlying cause of a bounce, such as a spam block, you should consider tagging the record, removing it from your active mailing list and attempting to find a replacement address. There’s little point in continuing to remail records that you know will bounce.
The same principle applies to soft bounces. However, you may want to set the rules for removal based on how frequently you turn your list. For example, if you turn your list every week and hit a “mailbox full” bounce, you may want to allow four or more bounces for the same reason before affecting removal.
On the other hand, if your list turn is monthly, you’ll want to consider a lower tolerance because the customer may not remember you if you wait four months before initiating remedial action.
Dave Lewis is an e-mail marketing consultant. He was most recently at StrongMail Systems (www.strongmail.com), a provider of e-mail delivery servers and software.