Why are some email messages bouncing back to me as undeliverable?
Email messages bounce back for a wide variety of reasons. Here are a few:
A) Invalid email address B) The recipient's mail server is down or not functioning properly C) The recipient's mail server is refusing to accept messages from you or mail source
The failed delivery notifications often contain the information necessary to determine why they are bouncing back. Here is a sample message:
In this case the message was denied because the recipient's email server refused the email due to some anti-spam measures. The first step to resolving an issue like this is to configure your external mail server settings. You will need to do this for your Master Administrator account and for any Employee accounts that send outgoing emails via the system. Here is an FAQ on this: