For the webmail - (yahoo or Gmail etc) if you make an account on one of them-
Also Instead of using their contact us form -
if you can get or find online somewhere the actual email address of the place you want to contact - just copy & paste it -when you are logged into your online webmail account to send it.
I totally forgot you can remove the passwords or change them on XP. If you have a XP CD. I've even done it long ago.