You really don't need to have ip included in form (besides the reason of it could be changed), just have it in mail text, etc:
mail('caffinated@example.com', 'My Subject', wordwrap("Line 1\nLine 2\nLine 3", 70));
to
mail('caffinated@example.com', 'My Subject', wordwrap("Line 1\nLine 2\nLine...