• Sending an email notification to the receiver to return the receipt after acknowledging it is called an Email read receipt. 
  • Receiving receipts online might not be reliable if the attached picture’s pixel is disturbed or the receiver declines it.
  • Many email solution brands offer different facilities like email tracking, end-to-end encryption, or customized read receipts for businesses to make it more efficient.  

Email has become a necessary communication tool in our daily lives, and with it comes the need to know if our messages have been received and read. 

Enter the world of email read receipts. But how do these work, and can we rely on them as proof of email delivery? 

Let’s delve into the mechanics and reliability of email read receipts.

What is an Email Read Receipt?

An email read receipt, often referred to as a return receipt, is a notification sent to a specific receiver for acknowledgment of the receipt. 

When the recipient opens the online mail, a message is displayed, prompting them to manually return the receipt after reading and checking. This system is heavily dependent on the recipient’s action, meaning you might not always get a response.

Some email tracking systems use a more covert method by embedding a tiny image or pixel in the email. When the recipient opens the email, the pixel is activated, notifying the sender. 

However, this method is not foolproof, as technology can sometimes fail to recognize when an email is opened. 

 Benefits of Using Read-Receipt in Outlook Email

The Mechanics Behind Reading Receipts 

One common method employed by email read receipts is the use of a 1-pixel image attached to the email. When the recipient opens the email, this tiny image is downloaded, triggering a notification to the sender. 

This download request carries the recipient’s IP and other information, giving the sender insights into when and where the email was read.

Another approach, especially in platforms like Microsoft Outlook, involves the sender selecting options to request read and/or delivery receipts for their messages. When the recipient opens the email, they might be prompted to send it back to the sender. 

However, it’s relevant to note that the recipient can decline to send the receipts after checking. Moreover, some email programs don’t support read receipts, making it impossible to force a recipient to send one. 

Read receipts work best in a business or organizational setting where everyone uses the same email service and has common productivity goals. 

The Reliability of Email Read Receipts

While the concept of email-read receipts sounds promising, they are not always reliable. For instance, the embedded pixel method can be disturbed if the recipient’s email server has image preview functions disabled. In such cases, even if the receiver opens the email, the pixel won’t activate.

Moreover, read receipts were initially designed as a way to ensure that servers were operational and that emails reached their destination, not necessarily to confirm that a person read the email. The Message Disposition Notification RFC 3798 clearly states that MDNs can be easily forged and should not be relied upon as a guarantee that a message was seen by the recipient.

Even tech giants like Google advise against relying on read receipts to certify mail delivery. They highlight that read receipts might not always work across email systems, leading to potential dysfunction in delivery and read confirmations. 

A More Reliable Alternative: Registered Emails

For those seeking a more reliable method to prove email delivery, registered emails might be the answer. This technology offered by eEvidence, doesn’t require the recipient’s intervention. 

The delivery receipt is automatically issued, even if the recipient doesn’t open the email or deletes it. This method legally certifies that the message and its contents have been sent and delivered to the recipients, providing more solid proof of email delivery. 

 Growth in the Number of Email Users Worldwide from 2017 to 2026

List of Email Solutions That Offer Read Receipts

  1. Microsoft Outlook: One of the most widely used email clients, Outlook allows users to request read receipts when sending emails. The recipient is prompted to send a notification back to the sender once the email is opened.
  2. Canary Mail: A privacy-focused email client, Canary Mail offers read receipt functionality without compromising user privacy. It also provides features like end-to-end encryption for added security and AI assistant capabilities.
  3. Gmail: While Gmail doesn’t offer traditional read receipts for personal accounts, its business and education users can request read receipts. However, the recipient has the option to decline.
  4. Thunderbird: An open-source email client developed by Mozilla, Thunderbird supports read receipts, allowing senders to know when their emails have been read.
  5. Apple Mail: Integrated into the Apple ecosystem, Apple Mail provides the option to request read receipts, though the functionality might vary based on the recipient’s email client.
  6. eM Client: A comprehensive email client for Windows and macOS, eM Client offers read receipt functionality, ensuring senders can track when their emails are opened.
  7. Mailbird: Popular among Windows users, Mailbird provides read receipt features, allowing users to track their email interactions more effectively.
  8. Zoho Mail: A business-focused email solution, Zoho Mail offers read receipt functionality, especially useful for teams and businesses to track email communications.
  9. Polymail: A modern email client with a focus on productivity, Polymail offers read receipts as part of its suite of features, allowing users to know exactly when their emails are read.
  10. Mailspring: A free, open-source email client, Mailspring offers read receipt functionality, ensuring users can keep tabs on their email interactions.

These email solutions, including Canary, offer varying degrees of read receipt functionality, catering to both personal and business users. Even if you’re looking for basic read receipt features or more comprehensive email tracking, there’s likely a solution on this list that meets your needs.


While email-read receipts offer a glimpse into the recipient’s actions, they are not foolproof. Their reliability can be compromised by various factors, from technology limitations to user preferences. For those seeking undeniable proof of email delivery, turning to registered emails might be a more viable solution.