Synology 218+ | Xibo 1.8x | Docker | E-Mail Notification/Task

You don’t need to do any port forwarding for email.

The container connects out to GMail servers. It doesn’t run an email server itself.

You need to make sure you’ve enabled support for “less secure apps” in your Google account. There’s a comment in the config.env file to that effect:

Your username for Gmail will be your Gmail email address, (ie othername@gmail.com, not just othername)