Originally Posted by sbonline
This could be something to do with the email settings in the recipients email.
Have you thought about creating a webpage for the email as well, replicating the design and links, but allowing recipients to view the mail online instead?
This issue is related to those individuals who provide us with invalid email addresses so the email never reaches the intended target. When this happens, the ISP forwards the email to one that we setup internally to process the bounces. We added a custom header to the emails to be able to tell which specific email had the most bounces and/or complaints
I hope that clears things up, i'm really stumped here