Why It Matters
In 1-to-1 business communication, read receipts provide confirmation that an important message was seen. But in practice, they're unreliable and often annoying. Most modern email clients either block read receipt requests by default or ask the recipient whether they want to send one -- and most people click "No." For bulk email, read receipts don't work at all; that's what tracking pixels are for.
How It Works
The sender's email client adds a Disposition-Notification-To header to the outgoing message. When the recipient opens the email, their client detects the header and (depending on settings) either automatically sends a receipt, prompts the user, or ignores the request entirely.
The receipt is a separate email sent back to the address specified in the header. It typically contains a machine-readable MDN (Message Disposition Notification) confirming the message was "displayed."
Quick Tips
- Don't rely on read receipts for important business communication -- follow up if you need confirmation
- For marketing and bulk email, use tracking pixels or link tracking instead; read receipts aren't practical at scale
- If you're an email admin, consider disabling automatic read receipt sending to protect user privacy