Posting of personal correspondence between yourself and another party whether it be from email or from private messages is not allowed. The only exception to this is if you get permission from the author, this permission must be posted by the author of the email or PM within the thread where you wish to quote the personal correspondence.
Has been changed too:
Posting of personal correspondence between yourself and another party whether it be from email or from private messages is not allowed unless you have permission from the author and they are a member here. This includes email that has been forwarded to you. This permission must be sent to the Admin or Mod via PM before you post the correspondence.
There's legal issues involved with this including copyright and privacy laws which will vary by state hence the reason for the rule change.