I manage a website for a band who sends out weekly newsletters to those who sign up for them. Within the last couple of months, a huge percent of these emails were bouncing back as undeliverable (more than half). Many were AOL and Hotmail, which our hosting company claimed they were aware of and were dealing with. However, many were not either of those and a couple were actual band members, so we know they weren't blocking them themselves! The band manager created a new email account for the band through his personal Comcast at home. He gathered up the email addresses from the web server and tried sending the newsletter from there -- again, a huge amount bounced back! Is it possible for someone (possibly a former disgruntled band member) to cause this type of mess? I really don't know what to do next. Any suggestions/help would be greatly appreciated!!