Sending a message to a new contact with InReach

Today, while I was in a remote area, I wanted to send a message to a friend I didn't have in my contacts, but I remembered his email address. I opened the Messenger app connected to the InReach Mini 2, but I couldn't send the message because I can only send it to people who have the Messenger app. I had to send it via InReach, which is a bit cumbersome. Once sent, the message the address e-mail appeared in the Messenger app. Is it possible that there's no way to send an email to a contact who isn't in your address book via Messenger?