Message Encryption in O365 is service that lets you send encrypted emails
to people outside your company. No matter what the destination-Outlook.com,
Yahoo, Gmail, Exchange Server, Lotus Notes, GroupWise, Squirrel Mail, you name
it - you can send sensitive business communications with an additional level of
protection against unauthorized access. There are many business situations
where this type of encryption is essential. Here are just a few.
bank sending credit card statements to customers over email.
insurance company providing details about the policy to clients.
mortgage broker requesting financial information from a customer for a
healthcare provider using encrypted messages to send healthcare
information to patients.
attorney sending confidential information to a client or another attorney.
consultant sending a contract to a client.
therapist providing a patient diagnosis to an insurance company.
Office 365 E3 and E4 users will get Office 365 Message Encryption at no
Setting up encryption
Administrators set up transport rules to apply Office 365 Message
Encryption when emails match specified criteria. Transport rules provide great
flexibility and control, and can be managed via a web-based interface or
Setting up the transport rules is simple. Administrators simply select
the action to apply encryption or remove encryption in the Exchange admin
You set up Office 365 Message Encryption rules in the Exchange admin
Once the admin sets up the rules, whenever anyone in the company sends a
message that matches the conditions, the message is encrypted using Office 365
Message Encryption. The outgoing message is encrypted before it is delivered to
the outside mail server to prevent any spoofing or misdirection.
Receiving and responding to
When an external recipient receives an encrypted message from your
company, they see an encrypted attachment and an instruction to view the
The encrypted message appears as an attachment in a message in the
recipient’s inbox, with instructions for how to view it.
You can open the attachment right from your inbox, and the attachment
opens in a new browser window. To view the message, you just follow the simple
instructions for authenticating via your Office 365 ID or Microsoft Account.
Once you are authenticated, the content of an
encrypted message appears.
The Message Encryption interface, based on Outlook Web App, is modern
and easy to navigate. You can easily find information and perform quick tasks
such as reply, forward, insert, attach, and so on. As an added measure of
protection, when the receiver replies to the sender of the encrypted message or
forwards the message, those emails are also encrypted.
reply to an encrypted message you’ve received, your reply is also encrypted.
-gleaned from Office Blogs