Microsoft have just released the Mail.ReadBasic permission into beta for the Microsoft Graph endpoint https://developer.microsoft.com/en-us/graph/blogs/new-basic-read-access-to-a-users-mailbox/ which is a much needed addition that allows the creation of automation and apps that can just access messages at a more meta information level without having access to the Body or Attachments. Privacy and security are always pressing issues especially around email so this can turn down the privacy concerns while also reduce the security concerns of giving full access to content. Lets look at one use case for this new permission which is getting the Message Headers from a Message that has arrived in a users Mailbox that you suspect might be spam but you want the header information to do some analysis. Normally if you wanted to build an app to automate this you would have to at least assign Mail.Read which would give full access to all email content in a Mailbox (either delegated or every
Pushing the Envelope in Messaging and Office 365 Development