Kostya,
Build: 1.5.1.12
Server: Smartermail Enterprise (CloudAccess.Net Cloudmail)
Reporting this on behalf of Ann; I'm not seeing this issue, she is though on both her phone (GSIII) and tablet (2012 N7), although for completely different emails on each device.
We've got some emails that seem to be identical copies of each other, e.g. you can mark one of them as read on the phone, perform a refresh, and the other will be marked as read as well. Delete one, the other is deleted.
Now, bear in mind it'll only be on her phone for this email. Her tablet will have the same issue for different emails but will show only one copy of the dupe on her phone.
So, now let's make this a little more wacky ; she found one instance a dupe on her phone, but 8 on her tablet, out of the 8 on the tablet, 5 were actually showing different time zone offset results

(1 hour difference between the two) - the one I looked at was from the West Coast and so was in PDT and we're on the East Coast so using EDT (this was from July, so Daylight savings was in effect). From what I could tell the SMTP headers on both were identical. Unsure why the dupes are showing the 1 hour offsets here.
So, now comes a
caveat emptor; all these emails were before 10/16 - an important date to possibly consider because that's when I did a conversion to move her from GMail to Smartermail.
That said, if it were an issue with the underlying mail store inside Smartmail, then I'd expect the problems to be visible on both devices for the same emails.
Both devices had the old GMail config blown away and a fresh new Smartermail config setup made before downloading emails.
Not sure on what logging you want and from what point here so, let me know when I should turn logging on and what action I should do that would force logging of these emails (
I'm going to take a guess and say I should just perform a refresh with logging on).
I fully expect that backing up the config, doing a Delete Data, restoring and re downloading will probably go a long way to 'fix' this, but it seems like an awful amount of work, besides, this fascinates me and I'd much rather we scalpel our way through this than dropping a nuclear bomb from orbit.
NB: I have tried upping the limit of checked emails to 10,000 (or whatever the maximum is) in attempt to get AM to re-evaluate what it has stored, but that didn't seem to help any.
R