Better Email stopped seeing after upgrade to 7.2.9

I have two machines in two different locations. Both send emails at midnight using Better Email as a confirmation that things are working. Yesterday I upgraded Better Email form 7.2.4 to 7.2.9 on one of my machines. It suddenly stopped sending emails. No error message - the emails are simply not arriving. I will attach some screen shots. Using apple SMTP server.

Any ideas why SMTP server would send OK from 7.2.4 but not 7.2.9? The machine still using 7.2.4 sends fine too.

Only difference between the Macs is 7.2.9 is running 10.13.6 - it is an older Mid 2011 iMac. 7,2.4 being run on 10.15 in newer machine. All using latest Indigo

The older machine is running High Sierra, right? So it's probably not the SSL issue.

The log shows the queue is not growing, so the plugin thinks the emails are being sent.

The only changes between 7.2.4 and 7.29 for the SMTP code was some updated logging. Nothing in the actual sending code changed.

I would create a new device-specific password for that machine and update passwords in the devices that use the iCloud servers.

I just tested 7.2.9 on my system, using the iCloud SMTP server. Worked fine.

Further color. I upgraded to 7.2.9 on the other mac and it still works.

Went back to the machine that will not send and created a new device. It thinks its sending using (based on the log) but no email arrives. I am using the same account fro sending, receiving, message, SMTP server (smtp.mail.me.com). Only differences I can think of are:

1) One machine is on FIOS, other is on Optimum Online
2) The machine that fails is a 2011 iMac running 10.13.6 (high Siera)

It worked until yesterday, too. Yesterday I (1) temporarily loaded an old DB file, then went back to my regular one; (2) upgraded Better Email; added a few new devices

Is there something else I can do to check?

Did you try creating a new app specific password, as I suggested above?

Yes I did.

I was able to create an app sepcific password on a gmail account I have and use gmail smtp server to send from the problematic machine.

Actually, here is the situation and I do not believe the problem is Better Email but some kind of SPAM filtering.

From the gmail account, I am sendign a test email to my me.com account, cc the gmail account. The gmail account receives the message, but the me.com account does not. For whatever reason, apple seems to be blocking emails from my me.com account to my me.com account ONLY when sent from my FIOS machine. Does that make sense?

I'm not sure it makes sense, but it's certainly possible.

One more observation and a workaround fix.

When I add my gmail account to the cc:field on the regular nightly send, my me.com account receives.

So:

Send from smpt.mail.me.com, use application-specific password.

a) Send from xxx@me.com to xxx@me.com - Apple filters the message out if sent from FIOS machine but not if sent from optimum online machine
b) Send from xxx@me.com to xxx@me.com cc xxx@gmail.com - the message is sent fine (and gmail is filtering message)