I've had this problem several times, and support seems unable to help. In a nutshell, I'm missing tons of email that I know wasn't downloaded.
In the last case (now), I was on vacation for two weeks (9/8-22), and checked webmail several times to access things like a couple of password verification emails, etc. (so I know the emails were actually there...).
I never have my home PC download email automatically, but only manually. No one has access to it, and the mail was in webmail when I did check it. When I returned home and downloaded it today, I only got email from 9/20 to today. Hundreds (probably over 1500) emails are not there (9/8-9/19).
Support only says (the last time this happened, a month or so ago) that someone had to have downloaded it and that they can't restore it.
Anyone have suggestions or any idea what could be happening here? I've been doing Internet email (heck, it's my day job, supporting this sort of thing... ), and I can't see where this could be going, unless someone else does have the passwords, but why would they only steal the mail these times? I'm not missing mail at any other times.
And, this time here is suspiciously close to the other mail problem DH had around 9/20. Could be a coincidence..... However, I can't put up with missing 13 days of emails; that's unacceptable.