Cmhall27,
This is not a solution but a suggested workaround, which I've detailed in entries to this thread, dated Oct 25, 2012, and Mar 8, 2013, both above.
I have found these choices good for my mental health: choosing to do spellchecking/editing without the use of the spellchecker (turned off in preferences, so it won't open up the suggested corrections pop-up box), or if you have your email preferences to check spelling before sending, limiting the corrections made to those identified by the spell checker, within the corrections box.
I discovered that if I attempt to do a word edit or spelling correction inside the body of the email (so, ignoring what's suggested in spell corrections pop-up box), the email gets sent prematurely, sans all the corrections I might need to make.
It is not an optimal solution to the problem, but one that I've learned to adapt to, until the Apple QC folks decide to escalate this issue to be properly fixed.