Hi Linwood;
Thanks for the quick response.
It was much simpler than that. In December last year, I changed ISPs, from ATT (arghh) to Suddenlink (also arghh, but faster and cheaper). That obviously changed my DNS, which I failed to update in the M1XEP. Why the unit kept sending emails for 10 months and all of a sudden stopped, no idea...
Once I updated the DNS, all things went back to normal, using both GMX and Gmail (port 587). Gmail used to not work a few years ago, which is why I got a gmx account in the first place. Back to Gmail again and happy.
BTW, this is part of the troubleshooting in the M1XEP manual... Well done ELK!
Thanks again for your help.