Signup/Login with a Social Network - No E-mail?

Hello,

One of the Social Networks I want to connect my users to doesn’t provide the user’s e-mail via their API. This is an issue for me as I need the e-mail in order to send them notifications, etc.

Likewise… can’t let the user update their credentials because they don’t have a password (since they were created via the Social Network signup).

Having them signup initially with an e-mail and password would be fine, but when I try to run the API to authenticate them for the other service, it creates another user which isn’t what I want…

What’s the best practice here? Has anyone found a way to solve this?

Thanks in advance!