On an increasing level, I cannot send mail from Outlook 2010.
The mail just sits in the Outbox.

I have tried send the mail by click the:
* "send / receive all folders" button on the "home" tab
* "send all" button on the "send / receive" tab

Normally I have to delete the mail, close / start Outlook and recreate the mail.

I am using a Gmail account.

How can I correct this?