Emails can be viewed from the Dashboard, under My Recent Communications.
or from the Records Page (Settings > Communications > Records)
The Status column will indicate if the email was sent, failed, delivered, or opened.
Indicates the email was sent and it was accepted by the recipients email server
The email could not be delivered to the recipients email server. Common reasons: Recipient email address does not exist or typed incorrectly, Domain name does not exist, Recipient email server has completely blocked delivery