So just got of the phone with Synology.
My new users on the DS1821+ are not receiving an email from the server (with the password and a welcome message). DSM 7.2 RC
So I find out the issues is the settings for DNS. I was using 184.108.40.206; and changing it to 220.127.116.11 works. I’m using a gmail account for the outbound traffic of the NAS.
So, i just thought i mention this, incase someone else has a similar issue.