Profile Manager not sending email invitations After installing a new copy of OSX Server I started the Profile Manager and wanted to add some users and enroll them for the VPP Managed Distribution (I am already registered for VPP).

In the VPP Managed Distribution section I hit "Resend invitation..." and a success message is displayed, but no invitation is received.

The possible causes:


Missing SSL certificate
Misconfigured e-mail in OSX server
Misconfigured DNS


I tried different email addresses and checked spam, but none of it helped.

Why are my invitations not sent?
When you acquire VPP app licenses for free applications, are they appearing in your Apps tab in the Profile Manager [device manager interface] sidebar?
Have your devices successfully enrolled to Profile Manager, and can you deploy configuration payloads/profiles to them?

We ran into this when getting OS X Server and PM up and running, and then realized you can distribute apps and books without requiring the user to approve these VPP invitations.
Unless you're attempting to deploy internal/enterprise apps, you can deploy App Store/VPP apps to devices or device groups as long as they are enrolled to Profile Manager (supervised or not, they should deliver as long as your config profiles are).
EDIT: You should also make sure that you have an APNs account and that APNs is enabled in your OS X Server, with an updated token.

If you‘re not getting Apple push notifications - https://support.apple.com/en-us/HT203609
Resolve issues with Profile Manager in macOS Server -  https://support.apple.com/en-us/HT201063