Hello!
I am using Dynu Email Store/Forward and Outbound SMTP Relay for my Synology NAS mailplus server. My domain is at GoDaddy.com.
I can confirm that I can receive/send emails from/to gmail domain, but any other domain just gets stuck in Email Delivery both ways. After 5 or so attempts email in queue just disappears and its not possible (or more probably I have not figure it out how) to diagnose the problem, as I cannot access any logs on Dynu side. Everything is marked Received/Completed on the NAS side.
Any advice would be highly appreciated, thank you in advance!