Bounce Message or Report

A bounce report, also known as a bounce message or a non-delivery report (NDR), is an automated email message generated by an email server to inform the sender that their email was not delivered to the recipient’s inbox.

Why an email can’t be delivered?

When an email is sent, it is routed through various servers before reaching the intended recipient’s mailbox. If there is a problem with the delivery of the email at any point in this process, such as an incorrect email address, a full mailbox, a blacklisted server, or a blocked email domain, the email may “bounce” back to the sender.

What information does such a bounce report have?

The bounce report typically includes information about why the email bounced back, such as the error code, the recipient’s email address, and a brief explanation of the reason for the failure. This information can be helpful in troubleshooting delivery issues and ensuring that future emails reach their intended recipients.

How does such a typical bounce report look like?

A typical bounce report includes information about why an email was not delivered, as well as details about the sender, recipient, and the email itself. The format of a bounce report can vary depending on the email service provider or the mail server generating the report.

Here is an example of a simple bounce report from a postfix mail server:

Subject: Undelivered Mail Returned to Sender

This is the mail system at host

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

Which language is a bounce report written in?

Bounce reports are typically written in English or the language used by the recipient’s mail server. However, the language used may vary depending on the email service provider or the mail server generating the bounce message.