Configuring Email Integration - How to reply and add comments

Hello!

Seeking help please! I have successfully set up the email integration so that emails create new tickets in YouTrack. However, I am unable to successfully reply to the email to add a comment. 

Can you please walk me through how to set that up? I've done a bit of research and playing around with the from and to email settings but that doesn't seem to work. Each reply I send just creates a new ticket. 

Also, can images be attached via email? How will they display in the ticket? Can you mention a user by name (@ user) and will it tag them like it typically does in an issue? 

Lastly, is there an easy way to pull the email of the reported in the ticket itself? I want to use this to track any users that do not have a youtrack account but still occasionally submit requests. 

Thanks for the support! Appreciate the help!