So, my OS X Mail program has worked more or less flawlessly for six months under Panther. (10.3.4 at this point). Then the other day I get this message out of the blue when trying to send a message: I can still receive messages with no problem. It doesn't matter who I send to, I get the same message every time, and of course using a different server or account didn't work either. I CAN send using webmail, so obviously the problem is somewhere at my end, not at Apple's. I think. Any idea why I'd have this problem? I tried calling Apple tech support just now but was on hold for 20 minutes and no sign of anyone picking up, so I hung up.