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       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.
       These examples are valid forms of the same address:

            Eric Allman <>
   (Eric Allman)

       The  domain  part ("") 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.

       The  local  part  ("eric")  is  often  a  user name, 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:


       (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.)

       The  real-name  part ("Eric Allman") 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 "", e.g. if it contains ".":

            "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.  Sometimes it works, but you
       should not depend on it.

       In the past, sometimes one had to route 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:


       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.

       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.

       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.




       binmail(1),  mail(1), mconnect(1), aliases(5), forward(5), sendmail(8),

       RFC 2822 (Internet Message Format)