| .\" Copyright (c) 1983, 1987 The Regents of the University of California. |
| .\" All rights reserved. |
| .\" |
| .\" @(#)mailaddr.7 6.5 (Berkeley) 2/14/89 |
| .\" |
| .\" Extensively rewritten by Arnt Gulbrandsen <agulbra@troll.no>. My |
| .\" changes are placed under the same copyright as the original BSD page. |
| .\" |
| .\" Adjusted by Arnt Gulbrandsen <arnt@gulbrandsen.priv.no> in 2004 to |
| .\" account for changes since 1995. Route-addrs are now even less |
| .\" common, etc. Some minor wording improvements. Same copyright. |
| .\" |
| .\" %%%LICENSE_START(PERMISSIVE_MISC) |
| .\" Redistribution and use in source and binary forms are permitted |
| .\" provided that the above copyright notice and this paragraph are |
| .\" duplicated in all such forms and that any documentation, |
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| .\" distribution and use acknowledge that the software was developed |
| .\" by the University of California, Berkeley. The name of the |
| .\" University may not be used to endorse or promote products derived |
| .\" from this software without specific prior written permission. |
| .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| .\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| .\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| .\" %%%LICENSE_END |
| .\" |
| .TH MAILADDR 7 2020-08-13 "Linux" "Linux User's Manual" |
| .UC 5 |
| .SH NAME |
| mailaddr \- mail addressing description |
| .SH DESCRIPTION |
| .nh |
| This manual page gives a brief introduction to SMTP mail addresses, |
| as used on the Internet. |
| These addresses are in the general format |
| .PP |
| user@domain |
| .PP |
| where a domain is a hierarchical dot-separated list of subdomains. |
| These examples are valid forms of the same address: |
| .PP |
| john.doe@monet.example.com |
| .br |
| John Doe <john.doe@monet.example.com> |
| .br |
| john.doe@monet.example.com (John Doe) |
| .PP |
| The domain part ("monet.example.com") is a mail-accepting domain. |
| It can be a host and in the past it usually was, but it doesn't have to be. |
| The domain part is not case sensitive. |
| .PP |
| The local part ("john.doe") is often a username, |
| but its meaning is defined by the local software. |
| Sometimes it is case sensitive, |
| although that is unusual. |
| If you see a local-part that looks like garbage, |
| it is usually because of a gateway between an internal e-mail |
| system and the net, here are some examples: |
| .PP |
| "surname/admd=telemail/c=us/o=hp/prmd=hp"@some.where |
| .br |
| USER%SOMETHING@some.where |
| .br |
| machine!machine!name@some.where |
| .br |
| I2461572@some.where |
| .PP |
| (These are, respectively, an X.400 gateway, a gateway to an arbitrary |
| internal mail system that lacks proper internet support, an UUCP |
| gateway, and the last one is just boring username policy.) |
| .PP |
| The real-name part ("John Doe") can either be placed before |
| <>, or in () at the end. |
| (Strictly speaking the two aren't the same, |
| but the difference is beyond the scope of this page.) |
| The name may have to be quoted using "", for example, if it contains ".": |
| .PP |
| "John Q. Doe" <john.doe@monet.example.com> |
| .SS Abbreviation |
| Some mail systems let users abbreviate the domain name. |
| For instance, |
| users at example.com may get away with "john.doe@monet" to |
| send mail to John Doe. |
| .I "This behavior is deprecated." |
| Sometimes it works, but you should not depend on it. |
| .SS Route-addrs |
| In the past, sometimes one had to route a message through |
| several hosts to get it to its final destination. |
| Addresses which show these relays are termed "route-addrs". |
| These use the syntax: |
| .PP |
| <@hosta,@hostb:user@hostc> |
| .PP |
| This specifies that the message should be sent to hosta, |
| from there to hostb, and finally to hostc. |
| Many hosts disregard route-addrs and send directly to hostc. |
| .PP |
| Route-addrs are very unusual now. |
| They occur sometimes in old mail archives. |
| It is generally possible to ignore all but the "user@hostc" |
| part of the address to determine the actual address. |
| .SS Postmaster |
| Every site is required to have a user or user alias designated |
| "postmaster" to which problems with the mail system may be |
| addressed. |
| The "postmaster" address is not case sensitive. |
| .SH FILES |
| .I /etc/aliases |
| .br |
| .I \(ti/.forward |
| .SH SEE ALSO |
| .BR mail (1), |
| .BR aliases (5), |
| .BR forward (5), |
| .BR sendmail (8) |
| .PP |
| .UR http://www.ietf.org\:/rfc\:/rfc5322.txt |
| IETF RFC\ 5322 |
| .UE |