In order to properly get your Gmail SMTP server working correctly, you will need to configure your form/plugin to use the correct SMTP settings. This will show you how to set up smtp properly in gmail.
Set up SMTP relay service
- From the Admin console Home page, go to AppsGoogle WorkspaceGmailRouting.
- Next to SMTP relay service, click Configure.
- Set up the SMTP relay service by following the steps in SMTP relay: Route outgoing non-Gmail messages through Google.
On your device or in your app, connect to smtp-relay.gmail.com on one of these ports: 25, 465, or 587.