Thanks, Niki, you're quite right, I haven't deleted any message, and on the rare occasions I do have to delete one I always tell the person concerned why I deleted it.

0x0, there is no way to 'be removed' from this site, you simply don't visit any more if you're not happy here.
I'm not sure why your email address wouldnt be valid any more, unless you've changed your usual email address, in which case its just as Niki says, change it in your profile. You can also change your username there.
If there is anything else I can help with then please let me know, but I'm not quite sure what the problem is?