Network Working Group D. Crocker Request for Comments: 2142 Internet Mail Consortium Category: Standards Track May 1997
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
This specification enumerates and describes Internet mail addresses (mailbox name @ host reference) to be used when contacting personnel at an organization. Mailbox names are provided for both operations and business functions. Additional mailbox names and aliases are not prohibited, but organizations which support email exchanges with the Internet are encouraged to support AT LEAST each mailbox name for which the associated function exists within the organization.
Various Internet documents have specified mailbox names to be used when reaching the operators of the new service; for example, [RFC822 6.3, C.6] requires the presence of a <POSTMASTER@domain> mailbox name on all hosts that have an SMTP server. Other protocols have defacto standards for well known mailbox names, such as <USENET@domain> for NNTP (see [RFC977]), and <WEBMASTER@domain> for HTTP (see [HTTP]). Defacto standards also exist for well known mailbox names which have nothing to do with a particular protocol, e.g., <ABUSE@domain> and
The purpose of this memo is to aggregate and specify the basic set of
mailbox names which organizations need to support. Most
organizations do not need to support the full set of mailbox names defined here, since not every organization will implement the all of the associated services. However, if a given service is offerred, then the associated mailbox name(es) must be supported, resulting in delivery to a recipient appropriate for the referenced service or role.
If a host is not configured to accept mail directly, but it implements a service for which this specification defines a mailbox name, that host must have an MX RR set (see [RFC974]) and the mail exchangers specified by this RR set must recognize the referenced host's domain name as "local" for the purpose of accepting mail bound for the defined mailbox name. Note that this is true even if the advertised domain name is not the same as the host's domain name; for example, if an NNTP server's host name is DATA.RAMONA.VIX.COM yet it advertises the domain name VIX.COM in its "Path:" headers, then mail must be deliverable to both <USENET@VIX.COM> and
<USENET@DATA.RAMONA.VIX.COM>, even though these addresses might be delivered to different final destinations.
The scope of a well known mailbox name is its domain name. Servers accepting mail on behalf of a domain must accept and correctly process mailbox names for that domain, even if the server, itself, does not support the associated service. So, for example, if an NNTP server advertises the organization's top level domain in "Path:" headers (see [RFC977]) the mail exchangers for that top level domain must accept mail to <USENET@domain> even if the mail exchanger hosts do not, themselves, serve the NNTP protocol.
For well known names that are not related to specific protocols, only the organization's top level domain name are required to be valid. For example, if an Internet service provider's domain name is COMPANY.COM, then the <ABUSE@COMPANY.COM> address must be valid and supported, even though the customers whose activity generates complaints use hosts with more specific domain names like SHELL1.COMPANY.COM. Note, however, that it is valid and encouraged to support mailbox names for sub-domains, as appropriate.
Mailbox names must be recognized independent of character case. For example, POSTMASTER, postmaster, Postmaster, PostMaster, and even PoStMaStEr are to be treated the same, with delivery to the same mailbox.
Implementations of these well known names need to take account of the expectations of the senders who will use them. Sending back an automatic mail acknowledgement is usually helpful (though we suggest caution against the possibility of "duelling mail robots" and the resulting mail loops).
These names are related to an organization's line-of-business activities. The INFO name is often tied to an autoresponder, with a range of standard files available.
MAILBOX AREA USAGE ----------- ---------------- --------------------------- INFO Marketing Packaged information about the organization, products, and/or services, as appropriate MARKETING Marketing Product marketing and marketing communications SALES Sales Product purchase information SUPPORT Customer Service Problems with product or service
Operations addresses are intended to provide recourse for customers, providers and others who are experiencing difficulties with the organization's Internet service.
MAILBOX AREA USAGE ----------- ---------------- --------------------------- ABUSE Customer Relations Inappropriate public behaviour NOC Network Operations Network infrastructure SECURITY Network Security Security bulletins or queries
For major Internet protocol services, there is a mailbox defined for receiving queries and reports. (Synonyms are included, here, due to their extensive installed base.)
MAILBOX SERVICE SPECIFICATIONS ----------- ---------------- --------------------------- POSTMASTER SMTP [RFC821], [RFC822] HOSTMASTER DNS [RFC1033-RFC1035] USENET NNTP [RFC977] NEWS NNTP Synonym for USENET WEBMASTER HTTP [RFC 2068] WWW HTTP Synonym for WEBMASTER UUCP UUCP [RFC976] FTP FTP [RFC959]
Mailing lists have an administrative mailbox name to which add/drop requests and other meta-queries can be sent.
For a mailing list whose submission mailbox name is:
there MUST be the administrative mailbox name:
Distribution List management software, such as MajorDomo and Listserv, also have a single mailbox name associated with the software on that system -- usually the name of the software -- rather than a particular list on that system. Use of such mailbox names requires participants to know the type of list software employed at the site. This is problematic. Consequently:
LIST-SPECIFIC (-REQUEST) MAILBOX NAMES ARE REQUIRED,
INDEPENDENT OF THE AVAILABILITY OF GENERIC LIST SOFTWARE MAILBOX NAMES.
In DNS (see [RFC1033], [RFC1034] and [RFC1035]), the Start Of Authority record (SOA RR) has a field for specifying the mailbox name of the zone's administrator.
This field must be a simple word without metacharacters (such as "%" or "!" or "::"), and a mail alias should be used on the relevant mail exchanger hosts to direct zone administration mail to the appropriate mailbox.
For simplicity and regularity, it is strongly recommended that the well known mailbox name HOSTMASTER always be used
Several Internet registries implement mailing lists for Autonomous System contacts. So, for example, mail sent to <AS3557@RA.NET> will at the time of this writing reach the technical contact for Autonomous System 3557 in the BGP4 (see [RFC1654], [RFC1655] and [RFC1656]).
Not all Autonomous Systems are registered with all registries, however, and so undeliverable mailbox names under this scheme should be treated as an inconvenience rather than as an error or a standards violation.
Denial of service attacks (flooding a mailbox with junk) will be easier after this document becomes a standard, since more systems will support the same set of mailbox names.
[RFC821] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821, Information Sciences Institute, August 1982.
[RFC822] Crocker, D., "Standard for the format of ARPA Internet text messages", STD 11, RFC 822, University of Delaware, August 1982.
[RFC959] Postel, J., and J. Reynolds, "File Transfer Protocol (FTP)", STD 9, RFC 959, Information Sciences Institute, October 1985.
[RFC974] Partridge, C., "Mail routing and the domain system", STD 14, RFC 974, CSNET CIC BBN Laboratories Inc, January 1986.
[RFC976] Horton, M., "UUCP mail interchange format standard", RFC 976, Bell Laboratories, February 1986.
[RFC977] Kantor, B., et al, "Network News Transfer Protocol: A Proposed Standard for the Stream-Based Transmission of News", RFC 977, University of California, February 1986.
[RFC1033] Lottor, M., "Domain administrators operations guide", RFC 1033, SRI International, November 1987.
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1035, USC/Information Sciences Institute, November 1987.
[RFC1035] Mockapetris, P., "Domain Names - Implementation and Specification" STD 13, RFC 1035, USC/Information Sciences Institute, November 1987.
[RFC1654] Rekhter, Y., et al, "A Border Gateway Protocol 4 (BGP- 4)", RFC 1654, T.J. Watson Research Center, IBM Corp., July 1994.
[RFC1655] Rekhter, Y., et al, "Application of the Border Gateway Protocol in the Internet", RFC 1655, T.J. Watson Research Center, IBM Corp., July 1994.
[RFC1656] Traina, P., "BGP-4 Protocol Document Roadmap and Implementation Experience", RFC 1656, cisco Systems, July 1994.
[HTTP] Berners-Lee, T., et al, "Hypertext Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996.
This specification derived from an earlier draft written by Paul Vixie. Thanks to Stan Barber, Michael Dillon, James Aldridge, J. D. Falk, Peter Kaminski, Brett Watson, Russ Wright, Neal McBurnett, and Ed Morin for their comments on that draft.
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