Joined: Oct 2014
Posts: 140
Bounced errors will have the reason they were bounced in the email. If its bouncing from multiple people, its possible that the eBrandon IP address has been blacklisted on email spam lists. Happens all the time. I just did a quick check and it doesn't appear on any of the major lists but that doesn't mean its still not on some obscure list that people shouldn't even be using.
Like I said, read the email and it will tell you why it was bounced 99% of the time.