Mail suddenly resending lots of old messages? Or a Mail mirage?

Hi Everyone,

I am using Mac Mail (4.5) on Snow Leopard 10.6.8. I have not migrated to iCloud yet because I am not on Lion.

Tonight, I logged into Mail on the mac and after working for a while, checked my sent mail folder for something. I noticed Mail claimed about 20 messages as sent today (at the same time, 6:41 pm) which I actually sent two years ago. I started to panic because these were job-related emails and this is embarrassing.

Checking my MobileMe sent folder online, I don't see any of these messages listed.

So I am hoping this is just a glitch with the Mail program.

I then rebuilt my mailboxes, and the sent time for each of the same messages changed to 8:12 pm! Still, none in the MobileMe sent file.

If this is just a Mail glitch, how do I fix it?

I welcome your input.

VC in Long Island City