We launched our “List Detective” back in 2002 to help our clients detect and eliminate unknown or dead addresses at the time they upload them to our system. List hygiene is still critical in 2008. In fact, Return Path’s Q2 2008 Reputation Benchmark report shows that just a single hit to a spam trap (an address that is on your list and shouldn’t be) can cause serious deliverability problems.

Stephanie Miller of Return Path wrote in her recent MediaPost article: “…the study found that legitimate commercial servers with even one spam trap hit saw their deliverability rate plunge to 38% versus 58% for servers with no spam trap hits. Similarly, IPs that appeared on even one of the top nine public blacklists had a deliverability rate of 35% versus 58% for mailers not listed on any of these blacklists.”

How do you minimize the risk of having a spamtrap on your list?  First, use explicit opt-in methods (unchecked boxes) when you capture names. To be doubly sure – use double opt-in, where the subscriber has to confirm their address before they are actually added to your list. Second, scrub your list from bounces regularly. Your boss may be angry in the short-run that your list is shrinking, but he’ll thank you later for higher deliverability and ROI.