This has been brought up numerous times before, and is related to the on-going ALT+Enter line break issue that occurs for everything else chat related.

Simply put, if you use the advertised ALT+Enter when sending mail, it shows up blank to a recipient, pics attached to show this:



Ever since Xbox Beta Launch this has been a problem, and continues to be a problem with everything that uses ALT+Enter, including chat box, Alliance / Personal Quarters Message Boards, Chat Shortcuts and so forth.

Please can this finally be addressed properly as the game was released over a year ago now and this is still broken.