From: Richard Shetron <guest2@sgeinc.com>

We run our own dns for sgeinc.com. I've always used mail.sgeinc.com as my incoming and outgoing server. At various times mail has been an alias for another machine. It's currently on the same address as sge.sgeinc.com. On the update forced on us on 2/22/24 or 2/23/24 it stopped working. It still works as an outgoing server but incoming POP3 it stopped working. It started working when I changed my incoming server to sge.sgeinc.com.

Maybe your SSL cert?

$ openssl s_client -connect mail.sgeinc.com:995 < /dev/null |&

openssl x509 -noout -text | grep DNS: DNS:sge.sgeinc.com, DNS:sgeinc.com, DNS:www.sgeinc.com

"mail.sgeinc.com" is not in your list of alternate names, hence your mail clients started rejecting the SSL certificate as invalid.

Joseph Tam <jtam.home@gmail.com>