I saw some information that Sue put in for John Ellsworth Bullers and wanted to chat with her to see if she had a copy of his Birth record?
You can usually click on the name of any other user which will open a message screen that will allow you to prepare and send a message to that user, even if you do not see an email address. If you do see the email address listed, you can also send a message directly to that other user by pasting their email address into your own browser and then SEND your message directly.
Hopefully, the person you address will see your message and respond to you, but there is no requirement for other users to reply to our messages.
Here is the knowledge article from the Help Center with instructions for contacting another user. It includes messaging from your computer as well as a mobile device.