User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release) Build ID: 20131120062258 Steps to reproduce: Sent a new mail with a hyperlink only in the the message body - no other text. Actual results: 'An error occurred while sending mail. The mail server responded: : We were unable to deliver your message. Please try resending your message by adding some text.. Please check the message and try again.' However, the message was dropped into the 'Sent' folder but was definitely not sent/received as I tested by sending same to myself. Expected results: The message should not appear in the 'Sent' folder. Ideally, the error message should contain an active button, 'Back to Message' which when selected would re-present the message to make appropriate amendments.

This looks like the message was rejected by the server. Yes, saving it to Sent is a bug, but I think it is already filed somewhere.