From the Edit Menu, click Mail & Newsgroup Account Settings.

The Mail & Newsgroupgs Account Settins window will appear.

Click on Outgoing Server (SMTP) from the column on the left. Outgoing Sever (SMTP) Settings will appear on the right.

Change the Sever Name from
"smtp.clarityconnect.com" to "smtp-relay.clarityconnect.com".

Make sure that the box next to Use name and password is check, and the User Name field is filled in.
Click OK button to save the new setting.
The change is now complete. You should be able to send messages again.