The name of the service (be specific) - One 2 One
The email address which is used to send messages - 11 digit phone number @one2one.net, e.g. 01234567890@one2one.net if the mobile number is 01234 567890.
Any limit on the length of the name of the sender, the subject, and the message - The message is limited to 160 characters.
I hope that will be enough info. :)