RFC 822 states:

      It often is necessary to send mail to a site, without  know-
 ing  any  of its valid addresses.  For example, there may be mail
 system dysfunctions, or a user may wish to find  out  a  person's
 correct address, at that site.
      This standard specifies a single, reserved  mailbox  address
 (local-part)  which  is  to  be valid at each site.  Mail sent to
 that address is to be routed to  a  person  responsible  for  the
 site's mail system or to a person with responsibility for general
 site operation.  The name of the reserved local-part address is:
 so that "Postmaster@domain" is required to be valid.
 Note:  This reserved local-part must be  matched  without  sensi-
        tivity to alphabetic case, so that "POSTMASTER", "postmas-
        ter", and even "poStmASteR" is to be accepted.

Likewise, RFC 5321 states:

4.5.1.  Minimum Implementation


Any system that includes an SMTP server supporting mail relaying or
delivery MUST support the reserved mailbox "postmaster" as a case-
insensitive local name.  [...]  The requirement to accept mail for
postmaster implies that RCPT commands that specify a mailbox for
postmaster at any of the domains for which the SMTP server provides
mail service, as well as the special case of "RCPT TO:<Postmaster>"
(with no domain specification), MUST be supported.

SMTP systems are expected to make every reasonable effort to accept
mail directed to Postmaster from any other system on the Internet.

When a netizen encounters a domain that fails to behave accordingly, is there anything that s/he can do to compel the domain controller to enforce the RFC, besides submitting the domain to rfc-clueless.org (the replacement for rfc-ignorant.org)?

  • I see there are some people voting to close this question. Please give your reason(s)!
    – user11574
    May 8, 2014 at 14:00

3 Answers 3


No, there is no way you can force some else to run their mail server 'properly' for any definition of 'properly' that you care to give. You can try mailing to other common addresses, or anything you find on their website (if they have one). You can, if you like, refuse to transact mail with them, but unless you are Google or something massive like that, doing so is more likely to get your users beating down your door, than them to fix their problems.

Now, in the case of the postmaster address, I suspect that you'll find LOTS of domains that don't do it right - well known addresses may be the target of copious amounts of spam, and some places turn them off, rather than waste time wading through the spam in order to find the one-a-month-or-less legitimate e-mail.

It may well be the wrong thing to do, but for a lot of admins, the time needed to deal with that address seems way too high for the benefits of it being there.

  • 1
    Back when RFC 822 was written, spam just didn't exist. Even unsolicited email from unknown senders was virtually always legitimate. Mail servers were commonly configured as open or semi-open relays, a practice which would very quickly get them onto actually used blocklists these days. Many mail servers were also configured to allow remote debugging (as I recall, that was one of the attack vectors used by the Morris worm). These days, unsolicited email from unknown senders is rather almost always illegitimate (mainly spam).
    – user
    Jan 13, 2015 at 8:23

Contact the email admin for the domain and ask them to change/fix it.

If you're a customer, take your business elsewhere.

Otherwise, there's not much you can do as the RFCs aren't laws, and they're definitely not enforceable.

rfc-clueless.org isn't for reporting sites that don't have every RFC covered, it's specifically for reporting "public" email servers/domains that don't communicated with all other public mail servers (equally).

  • 1
    It's not necessarily a simple matter to "contact the email admin" if postmaster@domain doesn't work. Also, rfc-clueless accepts submissions of domains breaching the postmaster requirement.
    – user11574
    May 8, 2014 at 1:22

Your question is quite old, but I have one more note on this subject.

I've seen a lot of cases where postmaster@domain is a valid address (you receive 200 SMTP code from server in response to RCPT TO:), but all mail coming to it is silently dropped, so the RFC is strictly followed, but nobody ever see postmaster incoming messages.

  • Thanks, but as you can see from the passage I quoted in my question, such behaviour does not strictly follow RFC 822.
    – user11574
    Jan 14, 2015 at 3:15

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