None, you need to use email relay: https://support.google.com/a/answer/176600
Hi guys,
I was successful in configuring gmail to send notifications and invitations.
To do this I had to use the following instructions:
Host: smtp.gmail.com
Port: 465
Security: SSL
User: seuusuario@gmail.com
Password: password email
Furthermore, it was necessary to configure the Gmail account to allow login to less secure applications, third party applications, I carried out the following steps:
Account > Manage Google Account > Security > Access to less secure apps: just activate and now the metabase will be able to log in to Gmail, which was previously being blocked.
I hope it helps.
Hugs