Despite the two existing threads, I’ve struggled to get a users secondary emial address to Sync via SCIM provisioning. 

Like many environments, our users have multiple email addresses that differe from their UPNs

The ‘Secondary Email Mapping’ thread simply says “add the SMTP to the secondary email alias’, but doesn’t explain how. The azure AS SCIM enhancements thread seems to go off on a different topic for user location. It isn’t clear how we might add the multiple additional email addresses users have except for manually adding them. 

Even with contacting effy, their instructions for adding 

urn:ietf:params:scim:schemas:extension:freshservice:2.0:User:_secondaryEmail

and mapping that to secondary emails inside of Azure don’t seem to work at all. 

Surely there’s a solution for this?