Have you found a solution?
Recently upgraded to 10.8.5 on an iMac and am experiencing this EXACT issue in my mail account. I am using a gmail account. Is everyone else with this problem using gmail?
If I move the curser into the body of the email to manually correct something, WHILE spellcheck is running, the email just FLIES out and gets sent prematurely! I do not hit "send," because the spell check is NOT FINISHED conducting its check. It sends prematurely.
This is a bizarre development. Since i have used the Mail program on this same imac for years, I have never experienced anyting like this. Only started seeing this regularly with the OS upgrade to 10.8.5.
Needless to say, far too many of my emails are being sent without proper editing! Please HELP! 😟 I do not want to be forced to use web-based email, but that's where I am headed!
Per Glenn's suggestion , I have looked for something called a "User Library" in Finder. I cannot locate such a folder. Even tried searching for it using "Spotlight" but no success. Does nayone have a fix? I was trying to locate a .plist file. When I searched i found NUMEROUS files containing that name. Thats as far as I got.
Thanks in advance !