CTFD - Mail Error - Connection unexpectedly closed: timed out

We have updated to CTFD Version 3.5.1 and configured the email server as follows: Mail Server: smtp-relay.gmail.com mail server port: 25 When I try to email a user, I get the error that it unexpectedly closed. I am able to telnet to smtp-relay.gmail.com manually and send a message from the server.