Right now we can only send Emails from SL with 4096 bytes of data
From th wiki:
( The length of the entire email is limited to 4096 characters, including the subject, message, and other headers (such as address), as well as CR + LF and the prepended lines to the body. )
Sometimes this is good enough but sometimes we need to send larger chunks of data and since mono will give us 64K to work with now is the time to allow for bigger emails !
Thank you.