[sumtechguy]

Also it is an easy way to stop a denial of service attack. If you let an infinite amount in that field. I can remotely overflow your system memory. The mail system can just error out and hang up on the person trying the attack instead of crashing out.

[fluoridation]

Surely you don't need the message to be broken up into lines just for that. Just read until a threshold is reached and then close the connection.