Mail 4.6 has gone into an endless loop

Mac OS X 10.6.8 (It's that way for a reason. I have upgraded my other computers to Yosemite)

Just today, Mail (4.6) has gone into an endless loop, retrieving the same messages starting July 26, 2015 up to the present minute over and over and over and never stopping. There was a power cut when the computer was on, and I had to fix my boot drive by booting from a CD and fixing my boot disc with Disk Utility. That worked fine, and all other programs seem to be working correctly. I have checked the permissions on the boot disc, and there were some errors, which were fixed. This didn't fix the Mail problem.

I logged on to my mail account using a browser, and there was nothing that seemed wrong on the mail server end. I grabbed the text for some new messages I need and then logged off.

If I delete the account and set it up again, will I retain my old messages? Is this a possible solution? Or . . . ?