MAILADDR(7)                   Linux User's Manual                  MAILADDR(7)

       mailaddr - mail addressing description

       This  manual page gives a brief introduction to SMTP mail addresses, as
       used on the Internet.  These addresses are in the general format


       where a domain is a hierarchical dot separated list of subdomains.  For
       example, the addresses

            Eric Allman <>
   (Eric Allman)

       are valid forms of the same address.

       The domain part (``'') may be the name of an internet
       host, or it may be a logical mail address.  The domain part is not case

       The  local  part  (``eric'')  is  often a user name, but its meaning is
       defined by the local software.  It can be case sensitive,  but  usually
       isn't.   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:

            USER%SOMETHING@some.where          machine!machine!name@some.where

       (These  are,  respectively, an X.400 gateway, a gateway to an arbitrary
       inernal mail system that lacks proper internet support, an  UUCP  gate-
       way, and the last one is just boring username policy.)

       The  real-name  part (``Eric Allman'') can either be placed first, out-
       side <>, or last, inside ().  (Strictly speaking  the  two  aren't  the
       same,  but the difference is outside the scope of this page.)  The name
       may have to be quoted using "" if it contains certain characters,  most
       commonly ``.'':

            "Eric P. Allman" <>

       Many  mail systems let users abbreviate the domain name.  For instance,
       users at may get away with ``eric@monet'' to send mail  to
       Eric Allman. This behavior is deprecated.

       Under some circumstances it may be necessary to route a message through
       several hosts to get it to the final destination.  Normally  this  hap-
       pens  automatically and invisibly, but sometimes not, particularly with
       old and broken software.  Addresses which show these relays are  termed
       ``route-addrs.''  These use the syntax:


       This  specifies that the message should be sent to hosta, from there to
       hostb, and finally to hostc.  Some hosts disregard route-addrs and send
       directly to hostc.

       Route-addrs  occur frequently on return addresses, since these are gen-
       erally augmented by the software at each host.  It is generally  possi-
       ble  to ignore all but the ``user@hostc'' part of the address to deter-
       mine the actual sender.

       Every site is required to have a user or user alias designated  ``post-
       master''  to which problems with the mail system may be addressed.  The
       ``postmaster'' address is not case sensitive.

   FREQUENTLY ASKED QUESTIONS and many mirrors store a collection of FAQs.  Please  find
       and  use  a nearby FAQ archive; there are dozens or hundreds around the
       world.  mail/inter-network-guide explains how to send mail between many
       different  networks.   mail/country-codes  lists  the top level domains
       (e.g.  ``no''  is  Norway  and  ``ea''  is   Eritrea).    mail/college-
       email/part* gives some useful tips on how to locate e-mail addresses.


       binmail(1),  mail(1), mconnect(1), forward(5), aliases(5), sendmail(8),
       vrfy(8), RFC822 (Standard for the Format of  Arpa  Internet  Text  Mes-

4.2 Berkeley Distribution         1995-06-24                       MAILADDR(7)