The first message said:
test - lastone
It was not the last one.
The next subject was multiple test. The body said more people. I sent it from Gmail to my SimAuthor address and another company address.
That is the whole record from the afternoon. One recipient worked, so I added another. Similar messages run through the fall and winter in both directions between Gmail and SimAuthor.
I did not put the configuration change in the body. I do not know now whether I was checking routing, an alias, spam filtering, DNS, or a mail client. The result was the useful part.
The message reached more people. Done for the day.
At SimAuthor, that tiny check sat inside a much larger setup. I supported an office of about sixty people, with Windows and Linux servers, Active Directory, DNS, firewalls, VPN access, workstations, engineering labs, and production services. Mail had to cross the same network edge as everything else.
When a delivery test failed, a long body did not help. Start with the shortest message possible. Confirm one address. Add the next address. Look at the headers if the route is wrong. Test the reply path when the inbound path works.
That explains why the messages are so bare, but it does not identify the change between them. There is no ticket attached to the thread. lastone does not prove a repaired spam filter or a DNS change. It only shows that I expected the first run to finish the check and then decided I needed one more with multiple recipients.
Operational work often left records like this. The system told me more than the body told anybody else.