"Fifty million people changed their email address last year," says Eric Groves. "How many of those are on your email list right now?"

…Not happy with your answer to that one? Don’t worry: Groves says a little regular maintenance can keep your list hale and hearty. Here are some of his choices for list-cleaning best practices:

Analyze bounce backs. Investigate why messages bounce, and remove any addresses with a hard bounce from your list. Also identify and correct typos like .con instead of .com.

Manage unsubscribe requests. If your email marketing service doesn’t process unsubscribes automatically, make this a top priority.

Monitor your "reply to" inbox. Because spammers have been known to use unsubscribe functions to verify an address, some recipients prefer to make the request by email. Check your inbox for them.

Re-engage inactive subscribers. Design a campaign for those who haven’t opened your emails for the last six months. "If this doesn’t work," says Groves, "remove them. Clearly, they aren’t interested."

Form one good habit. Set time aside after each campaign—or once a month—for analyzing data and tossing out bad addresses.

Good list hygiene pays off. "Your sparkling clean email list may shrink a bit, but will outperform your big, old, messy list any day," Groves concludes.

MarketingProfs. Click to read the article.