app.ini
config file [mailer] section:[mailer]
ENABLED = true
HOST = mail.mydomain.com:587
FROM = gitea@mydomain.com
USER = gitea@mydomain.com
PASSWD = `password`
Restart Gitea for the configuration changes to take effect.
To send a test email to validate the settings, go to Gitea > Site Administration > Configuration > SMTP Mailer Configuration.
For the full list of options check the [Config Cheat Sheet]({{< relref "doc/advanced/config-cheat-sheet.en-us.md" >}})