I'm currently in the the process of setting up a Single Sign On method for SP on demand, at the moment I have the users imported using the Provisioning App. However this assigns their login name as " John.Smith@Domain.com" where as our SSO uses the login name " JohnS@Domain.com" 

Obviously the SSO won't work in this situation. 

The only fix I've found at the moment is to manually add a second email ID for the user in the zoho control panel: https://business.zoho.com/cpanel/index.do#dashboard

Manually adding a second email ID is impractical since we have over 250 users at the moment, so the question is, is there a method to import users or quickly add a secondary email ID?

Regards

Thomas