If I'm using the The Tor Browser and a gmail account would my identity be safe. In other words would the receiver be able to find my IP address
I don't believe the recipient of the email would know your IP address if you send it using TOR. Although the organization that controls your email account (i.e. GMail / Google) would probably not know your IP address if you use TOR, they might be able to gather enough information about you to that it would be a concern. Perhaps you should use a throw-away email account to send the email, and TOR.
So, let's talk about how Tor Browser works with a website.
- Your browser connects to the Tor network
- The Tor network and browser hides your identity by making you look like every other user
- You exit the Tor network via an Exit node and reach the website. Unless you tell the website who you are, they can't see anything about you...except that you are using Tor.
Google hates Tor. Even if you want to just search the web using Google, there's a good chance that you will get a never-ending Captcha page because Google doesn't want people using Tor to use their service. That goes for Gmail as well.
A better option would be a free protonmail account. You can even access that without leaving the Tor network. You still need to verify your information with them but at least they are not openly hostile to Tor users and no, the recipient would not be able to see your IP.