Hmmmm....this won't help, but I upgraded Evolution on my RH9 distro the day after it came out using the Red Carpet utility. Everything worked fine and Evolution is fine. I wonder if it would be worth it, even though you probably already did this, to just re-enter all of the info on each mail account even though it's "right" now. It might re-set some stuff and make it work.
I am using Evolution for all of my e-mail and it has worked great for both accounts. But I thought that when I set it up (after the upgrade) that I might have had one time where it didn't let the mail go out, so I just re-entered my server settings and then it was fine. Hmmm...
Also, just a note. If you upgraded Evolution to 1.4, you might not have spell check anymore. You will have to download aspell again and also the latest dictionary.
With Red Carpet all of this is automated, but you still have to "seek it out" as it doesn't see this as a necessary option.