Get Notifications When Your Messages Are Read in macOS Mail

Enable this hidden feature using Terminal

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by Heinz Tschabitscher
An independent writer who has reviewed hundreds of email programs and services since 1997.
Updated March 18, 2019

By default, macOS Mail doesn't support read receipts — notifications that the recipient of your email has opened it; however, if you're comfortable working in Terminal, you can make the necessary modifications to start requesting read receipts from your email recipients.

Typically, the recipient is asked to confirm that the message has been opened, after which you'll get a message to that effect. While this isn't an actual guarantee that the content was read or understood, it does confirm that it hit their Inbox, and you can rule out delivery failure.

Here's how to enable this feature:

  1. Open Terminal at Finder > Application > Utilities.

  2. At the prompt, type:

    defaults read com.apple.mail UserHeaders

    Cut and paste the text above.

    Select Enter.

    If that command returns an error that reads, "The domain/default pair of (com.apple.mail, UserHeaders) does not exist," type the following, replacing Name and email@address with your own. For example:

    defaults write com.apple.mail UserHeaders '{"Disposition-Notification-To" = "John Doe <sender@example.com>"; }'.

    Then, type

    defaults read com.apple.mail UserHeaders

  3. You're done at this point unless the defaults read command above returns a line of values that starts with { and ends in }. If so, take the following steps to finish setting up read receipt requests.

    Terminal app in macOS showing defaults write com.apple.mail UserHeaders

  4. Highlight the entire line. It might read something like {Bcc = "bcc@example.com"; }, for example.

  5. Copy that highlighted line with the Command+C shortcut, but don't paste it yet. Instead, type this (but don't press Enter yet):

    defaults write com.apple.mail UserHeaders

  6. Put a space at the end of the line followed by a single quote, and then paste what you just copied so that it shows up after what was just typed. End it with a single quote.

    Use Command+C to copy and Command+V to paste.

  7. Insert "Disposition-Notification-To" = "Name <email@address>"; ' in front of the closing } character, again replacing Name with your name and email@address with your email address.

  8. Press Enter. The line might now read like this:

    defaults write com.apple.mail UserHeaders '{Bcc = "bcc@example.com"; "Disposition-Notification-To" = "John Doe <sender@example.com>"; }'.

For full knowledge and control over the fate of the emails you send in macOS Mail, you can employ a certified email service or use third-party software such as iReceipt Mail.

To Disable Automatic Read Receipt Requests

Turning off this setting is just as easy. As above, open Terminal again. Simply type the following, then hit Enter.

defaults delete com.apple.mail UserHeaders
Screenshot of Terminal app in macOS showing