• by Ross Fadner , June 17, 2004

EmailLabs has unveiled a solution for the problem of email bounce processing, or returned emails, advancing the existing standard through keyword analysis. The current industry standard email protocol, SMTP, recommends that network administrators and Internet Service Providers (ISPs) attach standard codes or numbers to bounce replies.

This is only a recommendation, however, which many email systems fail to follow. According to Loren McDonald, VP-marketing, EmailLabs, some bounce replies deliver the wrong codes because busy network administrators have little incentive to comply with the SMTP standards. McDonald says that marketers need to know the correct nature of a failed delivery in order to maintain a healthy list.

"We use our own crawling technology--the same one that's used for our spam content checker," McDonald says. Instead of relying on the inconsistent standard protocol, EmailLabs offers its clients a bounce handling solution that scans the content of a bounce reply, looking for keywords that denote a type of bounce, and then categorizes it into one of seven types:

• Blocked: Delivery was blocked by the receiving mail server. • Failed: Email address/user does not exist on receiving mail server. • Suspended: Email account is suspended on receiving server. • Soft Bounce: Failure to get a response from the receiving server. • Soft Bounce: (DNS-Related): Unable to locate receiving server. • Temporarily Failed: Temporary outage or offline state of receiving server. • System Misconfiguration: Receiving server isn't set up properly to receive email.

McDonald says that ISPs are generally good about bounce messaging, but network administrators don't really have an incentive to attribute the appropriate reasons to delivery failure messages, since network administrators--who he says usually have a lot of other duties--sometimes use the same code for delivery failures.

He adds that one of the main problems with the major ISPs is that they don't tell anyone what their standards are for delivery. If a sender has a certain number of bounces, some ISPs will block all future messages from that sender. "There's a lack of transparency on the part of ISPs. They don't reveal specific percentages--they figure if they told senders they'd also be telling spammers," McDonald says.

"Because ISPs will block marketers with high bounce rates," he adds, "it's important for them to be able to categorize the reason for bounces." McDonald notes that list management is critical for email marketers, and that it will help them retain the right names and discard the wrong ones.