Something to keep in mind if sending sensitive information, here is an excerpt from ET's privacy policy:
"Private Messaging
Your account will allow you to access our "Private Messaging" system. Although this system allows you to contact other members directly without your messages being publicly viewable by all site visitors, your private messages are openly accessible to Administrators of our site. Your private messages may be accessed at any time for the purposes of site administration, legal inquiries, or investigating your account for violations of our member conduct rules."
"Private Messaging
Your account will allow you to access our "Private Messaging" system. Although this system allows you to contact other members directly without your messages being publicly viewable by all site visitors, your private messages are openly accessible to Administrators of our site. Your private messages may be accessed at any time for the purposes of site administration, legal inquiries, or investigating your account for violations of our member conduct rules."