For the Invite, you seem to be asking about Intuit Link? That's how you invite the taxpayer, sending them an invitation email which attaches you to them, creating a portal that is secure for you and them to share and communicate. If you paid for this, it might help to understand the function. Here is a training site with videos (scroll down for ProSeries):

https://proconnect.intuit.com/link/training/

By the way, this is Peer Users. You are not contacting Customer Support or Tech Support or Sales. This is a web-based discussion forum. You might be getting forum platform notifications via email, but this is not secure and it is not email.