Becoming an effective email marketer requires constant list cleansing and hygiene. Most lists shrink by 30 percent each year due to subscribers changing email addresses (according to Return Path). In addition, ISPs sometimes recycle old email addresses as spamtraps aimed at catching commercial emailers with old, rented, or purchased lists. Spamtraps typically come in two varieties:
An email address published in a location hidden from view such that an automated email address harvester (used by spammers) can find the email address, but no sender would be encouraged to send messages to the email address for any legitimate purpose. These are also called “honeypots.” Since no email is solicited by the owner of this spamtrap email address, any email messages sent to this address are immediately considered unsolicited.
A formerly valid email address recycled by an ISP or anti-spam organization that has been invalid for more than 18 months. Without activity for an extended period of time, spamtrap owners can safely assume that the mailer hitting spamtraps purchased the list or does not have an ongoing relationship with the subscribers. Alternately, a spamtrap can be an email address that bounces for a period of time (if appropriately handled), bounce management would have removed it from a list. Mailing these types of spamtraps proves that a sender did not process bounces appropriately.
When a legitimate email marketer mails to a spamtrap, deliverability ...