For Whiston read this.
Personal Messages (PM)
RootsChat is all about community and communication for your family history research. And there are plenty of ways to communicate: Posting on the boards, Personal Messages (PM), E-mail, ICQ, AOL Instant Messenger (AIM) and Yahoo Instant Messenger (YIM).
While e-mail is a good way to correspond privately with members, it has several drawbacks: You must open your e-mail application to write and send the message; the recipient must open his/her e-mail application; check his/her mail and your message will mixed in with all the other mail and it can take sometimes several minutes to an hour for mail to reach the recipient.
As an alternative to e-mail, RootsChat offers a faster, more private method. The Personal Messages system provides instantaneous delivery to the recipient's RootsChat Inbox. The mail is sent and received entirely through RootsChat, so neither you nor the recipient have to open another program or leave RootsChat. Private Messages also gives both the sender and recipient greater privacy: No one's e-mail address is revealed. Personal Messages show only the username and name of both parties.
If a recipient isn't online, Personal Messages wait in the member's RootsChat inbox until the next time they log in and then reads and/or deletes them. RootsChat Private Messages are a self-contained, highly private e-mail system.
In general, there is no limit to the number of PMs you may send or receive,
(although we do hope you will empty your Inbox and Outbox ('Sent Items') regularly).
New members must make at least three postings before being allowed to use the PM facility.
Please note: If you are sending PMs to new members who have less than three posts you will receive an error message, that your limit, or allowed number has been reached. (note that it says your limit, although it actually refers to the recipient.)
Attachments are not allowed on PMs
As the name says, Personal Messages are personal and private - do not publish PMs on the public boards !