Where is the history feature in Office 365? Can I see if recipients have read my e-mail to them?

A read receipt confirms if your email was opened by the recipient.

To request a read receipt for an outgoing message in OWA, click the extended menu while composing a message and click show message options.

Once the message options box appears, check Request a read receipt and click OK.

User's who receive messages with read receipts in OWA may see the following message upon opening:

When the user has opened a message with read receipt enabled you will receive an email notifying you.

In iOS Mail, and e-mail for Android, read receipt responses are sent by default. Please note that some mail clients may allow user's to neglect sending read receipt responses.