The email envelope contains metadata that is essential for the delivery of an email message. This metadata is hidden from the recipient's view and includes the following information:
Sender's email address: The email address of the sender, which is used to identify the origin of the email.
Recipient's email address: The email address of the recipient or recipients to whom the email is being sent.
Subject: The subject line of the email, which provides a brief summary of the email's content.
Routing information: Information about how the email should be routed through the internet to reach its destination. This includes details such as the IP addresses of the sending and receiving email servers and any intermediary servers through which the email passes.
Message ID: A unique identifier assigned to the email message, which helps track the message's delivery status and prevent duplicate deliveries.
Timestamp: The date and time when the email was sent, which is used to track the chronological order of emails and ensure timely delivery.
While recipients do not typically see this information, it plays a vital role in the behind-the-scenes processes of email deliverability.