1. my $YourEmail = "mymail@mymail.co.uk";

This is going to fail with use strict. Change to single quotes.
2. Referers is a scalar being assigned a list and the single quote on the second element isn't closed.
3. $Message is uninitialized.

I'm surprised you even got this to run... try changing those and see what happens. Good luck.

The scary part is that it looks like the code I referred to in my abysmally-rated node Re: Email form.

Apparently it has come back to haunt me. (and in one day - not bad turnaround time)