Get User Email Address

Returns a user's email address. This API is only available to apps approved byAtlassian, according to these [guidelines](https://community.developer.atlassian.com/t/guidelines-for-requesting-access-to-email-address/27603).**[Permissions](https://confluence.atlassian.com/x/_AozKw) required**:Permission to access the Confluence site ('Can use' global permission).