Is there nothing else with it, such as an embedded graphic or url?

Nope. No url or embedded graphic. Just different numbers every time.

First check to see if the message is html or plain text. Sometimes they will have a clear pixel tracking link built in. Otherwise it is just a test message to make sure the address is valid.

Hi. It's just plain text. More are getting through every day - not in unmanageable numbers but it's annoying. I will tweak the filters even further.

Have seen this too ...
Perhaps just a spammer who's brain capacity is not sufficient to handle his automated new spam tool correctly ...
It's faster to recognize and easier to delete, though.

Kind regards,
R.

I got a lot of these this week as well. Plain text, no attachment, no links, just a few numbers. They could be probing to see whether they get a bounce back from different addresses. Looks like someone was updating their spam list.

Looks like someone was updating their spam list.

If that's the case, then it's nice to know there's at least ONE spam list I'm not on since I've never seen one of these.