Email Synch between AD and Azure AD using Azure AD Connect

In AD I have put the user's email in the following fields:

1. In the E-mail field under Properties/General
2. in the 'mail' field under Attribute Editor
3. in the 'otherMailbox' field under Attribute Editor
4. in the 'proxyAddressess' field under Attribute Editor

I have setup Azure AD Connect to synch ALL possible fields

And yet still in Azure AD, the 'Email & 'Alternate email' fields under Authentication contact info are still BLANK!!

'Anyone know what AD fields synch to fill the Azure AD 'Email' and 'Alternate email' fields?