Sometime Sunday evening my email died. Anyone sending me correspondence received a note from my server telling them of the permanent failure!
Delivery to the following recipient failed permanently:
Technical details of failure:
PERM_FAILURE: SMTP Error (state 10): 550 message to verify they are valid.”
It is now fixed, I hope. Just another unintended consequence of updating software (not mine, but software at my hosting company).
The new Cpanel update apparently overwrote needed files involving email services. We have since corrected the issue and you should not have further problems.
When I didn’t get any spam for a few hours, I knew there was a problem.