I had an email that showed up as being read. I had never opened it. I know for certain that i havent given out my password. It seems that some just show up that way.
I had the same problem with a Hushmail account.
It was a Trojan that logged keystrokes. I don't know
how I got it, but I did get rid of it. Scan your harddrive
for viruses and then scan for Trojans with this program: http://lockdowncorp.com/lddownload.html
Click on "click here to download" and follow the
instructions. This program will at least tell you if you
have a Trojan. You have to buy the program to remove
the Trojan.Once you get rid of the Trojan(if you even have
one), you need to set new passwords for all your email
accounts.