Postmaster

A postmaster is a mail server’s administrator and has the associated email address postmaster@domain.com. Mail servers route messages about errors in email sending or processing to this email address. Every domain that supports the Simple Mail Transfer Protocol (SMTP) for sending emails must have a postmaster address setup.

An example of a postmaster email is a “postmaster email delivery failure” message. This usually occurs when the outgoing mail server can’t relay an email to recipients. Google capitalizes on the idea of a postmaster role with its Google Postmaster tools, which enable brands to fine-tune control over sending and deliverability.