I googled and even found a Wiki page for MMP. I’ve seen the term in a few threads lately. What does it mean?
monday morning post
you know, I never knew that. Guess I should leave GQ and CS once in a while… 
For future ref, there is a thread where we provide explanations for most of the jargon or special terms that have come into use here: Beginner's Guide to Glossary of Terms on Straight Dope Message Boards - About This Message Board - Straight Dope Message Board
But only the first two dozen or so really qualify as MMP’s.
Regard: In the thread linked just above, post #42-75 are MAP’s and 76-102 are MEP’s. Flutterby and the subsequent 31 posters have the unmitigated effrontery to drop a TMP into a thread clearly labeled MMP.
Then we’re treated so a liberal sprinkling of TAP’s, TEP’s and finally the expected WMP’s (pronounced “whumps”), WAP’s and WEP’s.
Nothing is madness, if not that.
Silly me, I knew that. Er … I was just testing you. Yeah! That’s it.
Thanks all for the responses.
Spelled out, it is mump, and usually plural, mumps. A childhood disease. 
And oddly, people who participate in the MMP have recently decided to be called Mumpers, although it has nothing to do with the childhood disease.
And Patty, the MMP periodically starts on Sunday (going by U.S. time zones), so there are cases where the first post is either an SEP or SNP.
I think I was better off not knowing any of this…