Problems with mail program sending emails?

Many times now mail has troubles sending outgoing messages. It displays a popup window that says that it could not send message using the server.

I am using gmail with POP and I never have a problem with their service when sending within their gmail website but I often have issues with mail.

This has also occurred with another email account I use that is not using gmail.

At other times messages will show as being sent (with the loading wheel) but it will just keep loading and loading and sometimes take 5-10min to send a message.

I have a perfect internet connection so that's probably not the problem.

Any suggestions please let me know thanks.


Dorian