how to make email page customized according to my requirment

Hi. I want to chnage the page layout where text message is written. You know I mean, for example I want following items typed so that when ever any one click my email address he gets the page opened with these heading in the page and can not alter.
Like
NAME:
DATE AND TIME (THESE SHOULD APPEAR ON AUTO AND CAN NOT ALTER)
SUB:

THANKS