In this article Ken Magill reminds us that if enough recipients think our e-mail program is garbage, no e-mail service provider in the world will be able to prevent spam complaints, and the resulting delivery troubles. Likewise, if we refuse to clean dead addresses off our list because one of those addresses just might, maybe, someday make a purchase, there isn’t a single ESP out there who will be able to stop Yahoo, AOL, and Microsoft from diverting our messages into recipients’ spam folders or blocking them altogether.
He's dead right! So is this quote:
That we still have marketers—the majority of them, apparently—who believe that the ESP they choose will have a significant effect on their deliverability means some ESP reps are selling marketers on lies, or the marketers are deluding themselves.