gogs/conf/auth.d/smtp.conf.example

# This is an example of SMTP authentication
#
id           = 103
type         = smtp
name         = GMail
is_activated = true

[config]
# Either "PLAIN" or "LOGIN"
auth            = PLAIN
host            = smtp.gmail.com
port            = 587
allowed_domains = 
tls             = true
skip_verify     = false