Outlook 2011 for MAC – error -50 Unresolved Recipients – when sending to a single email address – email goes out, but error is reported

Outlook 2011 for MAC is setup with 3 accounts.

• The Default account is setup to retrieve from one server, and send through another server, as the 'incoming' mail server does not allow outgoing mail.
• The next account is setup the same way, with the incoming using a different user/password, but the outgoing mail is the same.
• The third account uses the same incoming mail server as outgoing.

The issue is with the default account.

When you create a new email account, and send, the email does go out out and does get delivered, but outlook reports the error -50 Unresolved Recipients.

There is only one email in the Send To prompt.

i tried deleting the account, and setting it back up as the default, but it still reports the -50 Unresolved Recipients error.

Does anyone have any suggestions as to how i can get this to stop reporting an error, when there clearly isn't one?

Thanks,

Earl