Thanks for the reply. It's a POP acct but I think the problem is more serious. Now I cannot even open my email. On my desktop, I'm replying from my iPad. Also my hard drive is all of a sudden at capacity so the whole computer seems useless. Thinking of trying to back up everything to an external and rebooting
You might get some free space in Safe Boot...
Then try a Safe Boot, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, empty trash while in Safe mode.
(Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive & clear caches.)
If perchance you can't find your install Disc, at least try it from the Safe Boot part onward.