Some email clients use the date of the time the email was sent, according to the sender's computer.
Although using a system such as gmail or hotmail would be harder to contest, you might have trouble convincing a judge or jury of that. Royal Mail is so deeply ingrained into our society, people will take the date stamp as correct without question.
( SuperMatt, Sun 21 Jun 2009, 19:45, archived)

but you could have steamed the letter open
but really i think you're right
/devils advocate
(rigby happened on (and with added toothache), Sun 21 Jun 2009, 19:48, archived)

I was just thinking that
I'm sure there are more things you can do to help prove it though.
( SuperMatt, Sun 21 Jun 2009, 19:48, archived)

JUST DO AS YOURE BLOODY TOLD.

( rosalicious i fucking love youve been framed, Sun 21 Jun 2009, 19:51, archived)