🚀 go-pugleaf

Hello,
strange thing is happening since yesterday.
Yesterday, afternoon i received a mail and after reading it I quit the mail
and went back into mail to extract the message i had recieved few minutes back.
Surprisingly, that mail is not there. where in the world that mail go which
i had read few minutes back. Did i delete? no, even if I deleted it should be
in the waste basket [ My deleted mails sits in the waste basket till i purge 
them]. Since then, all my mails are disapparing as soon as i read them.
What?, is this a virus. I have never experienced this kind of stuff before.
Has anyone come across this?
Ours is a Vax Cluster with bunch of Vaxstation 3100's and 2000's. 
I am not able to check with my users whether they have experienced the same 
problem [ no one is around to ask till Jan 3rd!!]. 
let me know if you have  any solution to this problem.