Mail

In mail, I have a Gmail account. When I create a new message, and click send ,the message immediately goes to the outbox and remains there.

Then a dropdown box appears asking to send using the selected server. However, it indicates that the Gmail server is "offline." Nothing I try will let me send that message. This does not happen with iCloud mail.

I can use my iPhone and/or my iPad to send Gmail messages. I am currently using OSX 10.10.4 (beta), and IOSx beta on my iPhone & iPad.

Any suggestions as to how to fix the iMac problem?

Thanks,

JVH