I hope you all are well. I just now noticed that the email addresses associated with the default domain I am using for service, stopped receiving external emails back in April. I have not made any changes to any records and have this set up on the side where the domain is actually hosted.
Testing, I am able to send and receive between the two accounts. When I attempt to send email in from external email I have, I receive nothing. I have reviewed Message Tracking and it is saying emails are being rejected. This was an email I was actually waiting for and hence sprung about this investigation.
I will continue to dig in and your advise is greatly appreciated. I also will have to log in here periodically as the email address associated with this account is the one that is not receiving external emails.