can't send emails, but can receive.

For about a week messages I send go into the outbox and no further. I can receive messages but can’t send.

Are you getting any error messages? What happens when you click Send and Receive button?

8:38:11 AM "An attempt was made to access a socket in a way forbidden by its access permissions "

Then it brings in my new messages.

Most likely the socket is held by some process. Use netstat -o to find which one.

What OS are you using?