Zombie addresses - or unengaged addresses - are subscribers which have stopped interacting (opening or clicking) with your messages. They're a danger to the healthy portion of your list.
These days, the major mail providers (Aol, Gmail, MSN, Yahoo) place a heavy emphasis on user interaction when assigning your sending reputation and determining message placement. If you repeatedly deliver messages to subscribers who never interact or respond (zombies), the mail providers are more likely to treat your messages as junk.
Reachmail provides a handy feature for clearing the zombie addresses out of your lists. In the 'Export List' feature, we've added the option to export all unengaged addresses for a specific range of days. To access this option select 'Export List' from the action menu of any list. On the following screen, expand the Advanced Options section, check the 'Export ... NOT engaged ...' option, adjust the date range and click export. The resulting list can be used as a suppression list or as a base list for Compare and Remove. Keep in mind that a list has to have been delivered to at least 5 times before this feature becomes active and that the smaller the provided date range, the large the result set. Watch the Video