Synology Mail Server - Add-on Packages | Synology Inc.
Synology Mailplus | Synology Inc.
How to set up Synology MailPlus with your own domain name| Inbound SMTP relay | Outbound SMTP relay
Got scared today with this warning. So, for having my Synology NAS to send me email, do I need to grant all privileges to them? Can I change this for SEND EMAIL
Disable monthly disk report email | Synology Community