Email I try to send to att.net addresses is failing due to prodigy.net servers not using TLS
I send a sports newsletter from my server every couple of days and severeal of my subscribers have att email addresses (@att.net, @sbcglobal.net, @pacbell.net, etc.). For the past 3 days, i.e. starting on 1/20/2020, many of my emails to those subscribers have been failing (they've been fine for years before now). I first noticed this in my email send logs (for one email I was trying to send to my own email address, [email scrubbed]):
cwd=/usr/local/cpanel/whostmgr/docroot 4 args: /usr/sbin/exim -v -M 1iugtK-0009l9-2s
Sender identification U=tourna D=tournamart.com S=[email scrubbed]
Connecting to al-ip4-mx-vip1.prodigy.net [126.96.36.199]:25 from 188.8.131.52 ... failed: Connection timed out (timeout=5m)
H=al-ip4-mx-vip1.prodigy.net [184.108.40.206] Connection timed out
Connecting to ff-ip4-mx-vip1.prodigy.net [220.127.116.11]:25 from 18.104.22.168 ... failed: Connection timed out (timeout=5m)
H=ff-ip4-mx-vip1.prodigy.net [22.214.171.124] Connection timed out
Connecting to al-ip4-mx-vip2.prodigy.net [126.96.36.199]:25 from 188.8.131.52 ... failed: Connection timed out (timeout=5m)
H=al-ip4-mx-vip2.prodigy.net [184.108.40.206] Connection timed out
Connecting to ff-ip4-mx-vip2.prodigy.net [220.127.116.11]:25 from 18.104.22.168 ... failed: Connection timed out (timeout=5m)
H=ff-ip4-mx-vip2.prodigy.net [22.214.171.124] Connection timed out
== [email scrubbed] R=dkim_lookuphost T=dkim_remote_smtp defer (110): Connection timed out
Other emails I send that do not end up using those prodigy.net servers go through just fine. I did a little more digging and found on https://ns.tools/prodigy.net that the above servers do not support TLS:
al-ip4-mx-vip1.prodigy.net [126.96.36.199] does not accept TLS.
al-ip4-mx-vip2.prodigy.net [188.8.131.52] does not accept TLS.
ff-ip4-mx-vip1.prodigy.net [184.108.40.206] does not accept TLS.
ff-ip4-mx-vip2.prodigy.net [220.127.116.11] does not accept TLS.
while I believe my outgoing server requires TLS and so I THINK that is probably my problem. I really don't want to have to configure my outgoing server to not use TLS but is that my only option? I was on the phone with multple AT&T departments for hours today and none of them could tell me even who at AT&T to discuss this problem with.