all major US carriers received text messages overnight that appear to have been sent around Valentine's Day 2019

Sat Nov 9 21:08:53 UTC 2019

This can be a "curse" of highly available servers which stay up for a
year or more, some of mine will.

A mail delivery process locks messages in the queue for delivery and
then the process hangs.

Subsequent delivery attempts will honor the lock so they never go out,
nor are they even timed out.

It's not a terrible idea to have a scheduled process, like once a day,
which kills all delivery processes just for this reason, or any which
are more than, say, an hour or two old. It's an easy script to write
and mail delivery programs are or should be resiliant to receiving a
kill signal.

There are other scenarios possible but one would have to know their
entire software and network architecture to speculate.

-- 
        -Barry Shein

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