In December I used one of my email lists and had 21 bounce backs.  I did not change anything in the list, but sent another email in January and got 285 bounce backs.  Some of them are from gmail which is pretty standard.  There was nothing tricky about the email format.   I'm wondering if: a). People have blocked other Constant Contact users and wound up having ours blocked as well (Is there something Constant Contact changed?) or b).  People using certain email apps (Outlook?) have been blocked.  (Is there something that Microsoft has changed?)   Thanks, Liz   ... View more