Postmaster (computing)

In computers and technology, a postmaster is the administrator of a mail server. Nearly every domain should have the e-mail address postmaster@example.com where errors in e-mail processing are directed. Error e-mails automatically generated by mail servers' MTAs usually appear to have been sent to the postmaster address.

Every domain that supports the SMTP protocol for electronic mail is required by RFC 5321 and, as early as 1982, by RFC 822, to have the postmaster address. The rfc-ignorant.org website used to maintain a list of domains that do not comply with the RFC based on this requirement, but was shut down in November 2012. The website RFC² Realtime List expanded to include rfc-ignorant's lists after they shut down.

Quoting fromte> Any that includes an SMTP server supporting mail relaying or deliMUST support the reserved mailbox "postmaster" as a case-initive local name. This postmasdress is not strictly necessary if the server always returns 554 on connection opening (as describeection 3.1). The requirement to accept mail for postmaster implies that RCPT commands which specify a mailbox for postmaster at any of thins for which the SMTP server provides mail service,ell as ST be supp

<bloc SMTP systems are expected to make every reasonable effort to accept mail directed to Postmaster from any other system on the Inch as to contain a denial of service attack or oMTP server may block mail dire Postwever, such arraents SHOULD be nalored so as to avoid blocking messages

Since most domains have a postmaster it is commonly targeted by [[e-mai operations. Even if not directly spammed, a postmaster address may be ] spam from other servers that mistakenly trust fake return-paths commonly used in spam. <! spammer tries sending email to someone@somedomain.com, and it bounces (due to any number of reasons) and the fake retuyourdomain.com, then an automatic email will be generrdomain.com informing

External links

• RFC 5321: The SMTP Protocol