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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:

            John Doe <>
   (John Doe)

       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

       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:


       (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 ("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 ".":

            "John Q. Doe" <>

       Some mail  systems  let  users  abbreviate  the  domain  name.   For  instance,  users  at may get away with "john.doe@monet" to send mail to John Doe.  This behavior is
       deprecated.  Sometimes it works, but you should not depend on it.

       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:


       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




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

       IETF RFC 5322 ⟨


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