MFMessageErrorDomain error 1028

I've been having a continuing problem with mail. "MFMessageErrorDomain error 1028" is only one of them. I'm not sure if it's connected to the others I've been having, but this message pops up randomly while mail is open and while its closed. Every time i do open mail, its tries to send a message I meant to send a long time ago, and it just wont seem to send. Draft after draft appears in the draft box every time I open mail and its rather strange that it won't let me stop the sending. It says that port 993 has timed out, and I know that has something to do with the message not sending, but it won't let me change the number when I go to preferences. I obviously can't send or recieve messages at all, and it's getting rather annoying! I tried to figure out how to start over but I don't know how to configure anything. Everything is updated. Anyone know what I can do? Its a bit difficult to explain what's going on since I can barely understand it myself, so I apologize it that made no sense!

-Renee