Office 365 tenants can use Exchange transport rules to apply autosignatures to outbound email, including messages protected with encryption. You can even include some properties of the sender extracted from Azure Active Directory, and you can add an exception so that the autosignature isn’t applied to replies.
Exchange Online will soon capture audit records for any access to a message in a mailbox. Initially, the audit records will not be ingested into the Office 365 audit log, but that will happen in the future.
Encrypted email is becoming more common within Office 365. Things usually flow smoothly when sending protected messages to email recipients, but other Office 365 recipient types like Teams and Yammer might not be able to handle protected email.
The Exchange Online Managed Folder Assistant (MFA) runs in the background on a workcycle basis to make sure that mailboxes are processed at least once a week. Most of the processing involves mailbox and Office 365 retention policies and runs smoothly, but how do you know what MFA has done?