Today I had the 7th instance.

As the circumstances haven't changed - only the date, I'll leave the most recent question below.  I've had the same (which is to say none) response to the previous questions, as well...

Unknown version of WLM (I don't know how to find it)

POP3

Message rules

 I have raised this issue, complete with screen snips, and followed up several times as it happened again, in the past.

So far not a single response, whether from Microsoft or someone watching.  Perhaps someone here has dealt with the same issue and has a solution.  Here's what's up:

I monitor 4 different accounts.  Each of the accounts appear to be fine on their own (nothing amiss in those accounts).  To make my life simpler and to see all at the same time, I have a message rule which copies all messages to a subfolder in the main account (which for identification I call NullAllMail).  A wrinkle in WLM prevented me from having everything copied to the 'inbox' which came with that "account" being set up.  So, I created a subfolder called AllMail or something similar.  I don't actually directly remember as it disappeared after a while of perfect use.

That's been the story for what is now 6 times.  I raised this issue, complete with screen snips, and followed up several times in the past, with Microsoft.  I gave up trying to amend those posts after the 3rd or 4th iteration, as it was not getting any followup.

So far not a single response, whether from Microsoft or someone watching.  Perhaps someone here has dealt with the same issue and has a solution.

As, so far, all 4 individual accounts seem unharmed.  But because this contains material going back to the early 90s, imported from various upgrades in the past, with OE, I'm terrified that this may entirely disappear.  And, in fact, there HAVE been some degradations of some of the storage folders, as I save each account every six months.  One of them (maybe more; I haven't done a folder-by-folder inspection) has all but a half a month which has disappeared.  As I have repeatedly had to go back into these in order to fetch some data or information, to have this happen is catastrophic.  And trying to find something in a backup is beyond difficult, as to restore would overwrite whatever I currently have.

Back to the original, it has always happened as I have 'permanently delete'd items I don't need, such as a news feed mailing list, or a facebook notification, or whatever that I don't want to save.  That may have some clue?

(Current instance did NOT include that - I was shuffling back and forth between my browser and WLM - so it may well be of no significance.)

Is there a trick to finding an entire folder?  I'm beyond frustrated; this is the name I've assigned to the current one, which I haven't yet populated (copying thousands of mails takes a great long while, never mind the error messages which makes it such that I have to do it in bits and pieces):  7thMofoGDammitAllMail .  That was preceded by 6th, 5th, etc., each with somewhat less blistering names than the successor.

(My bad.  On re-reading, I realized that I missed one iteration of my mail names; the one which disappeared today was actually #8; thus, this is the 9TH time this has happened.)

Bleah.

(Is anyone out there?  Does anyone actually read these?

This is from the 'about' page:

Version 2012 (Build 16.4.3528.0331)
Copyright © 2012 Microsoft Corporation. All rights reserved.

Microsoft® Office 2010 Proofing Tools
© 2010 Microsoft Corporation.  All rights reserved. 

Is there a clue in here somewhere??)