I am getting the following error when trying to send group emails.
WHY? PLEASE FIX THIS!!!
Message could not be sent. Error message from mail transport server: 452 - 452 4.1.1 ... temporary failure
Did you ever solve this? I am having the same problem. Houdini Museum, Scranton, PA
This 4 year old post kind of explains it----------
Something is wrong with one or more of the addresses you are trying to send to. How many contacts are in this group? Maybe you could try sending a test message to each one separately to each one to see which one is the culprit?