1MAILADDR(7) Linux User's Manual MAILADDR(7)
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6 mailaddr - mail addressing description
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9 This manual page gives a brief introduction to SMTP mail addresses, as
10 used on the Internet. These addresses are in the general format
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12 user@domain
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14 where a domain is a hierarchical dot-separated list of subdomains.
15 These examples are valid forms of the same address:
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17 eric@monet.berkeley.edu
18 Eric Allman <eric@monet.berkeley.edu>
19 eric@monet.berkeley.edu (Eric Allman)
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21 The domain part ("monet.berkeley.edu") is a mail-accepting domain. It
22 can be a host and in the past it usually was, but it doesn't have to
23 be. The domain part is not case sensitive.
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25 The local part ("eric") is often a username, but its meaning is defined
26 by the local software. Sometimes it is case sensitive, although that
27 is unusual. If you see a local-part that looks like garbage, it is
28 usually because of a gateway between an internal e-mail system and the
29 net, here are some examples:
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31 "surname/admd=telemail/c=us/o=hp/prmd=hp"@some.where
32 USER%SOMETHING@some.where
33 machine!machine!name@some.where
34 I2461572@some.where
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36 (These are, respectively, an X.400 gateway, a gateway to an arbitrary
37 internal mail system that lacks proper internet support, an UUCP
38 gateway, and the last one is just boring username policy.)
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40 The real-name part ("Eric Allman") can either be placed before <>, or
41 in () at the end. (Strictly speaking the two aren't the same, but the
42 difference is beyond the scope of this page.) The name may have to be
43 quoted using "", for example, if it contains ".":
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45 "Eric P. Allman" <eric@monet.berkeley.edu>
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47 Abbreviation.
48 Many mail systems let users abbreviate the domain name. For instance,
49 users at berkeley.edu may get away with "eric@monet" to send mail to
50 Eric Allman. This behavior is deprecated. Sometimes it works, but you
51 should not depend on it.
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53 Route-addrs.
54 In the past, sometimes one had to route a message through several hosts
55 to get it to its final destination. Addresses which show these relays
56 are termed "route-addrs". These use the syntax:
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58 <@hosta,@hostb:user@hostc>
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60 This specifies that the message should be sent to hosta, from there to
61 hostb, and finally to hostc. Many hosts disregard route-addrs and send
62 directly to hostc.
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64 Route-addrs are very unusual now. They occur sometimes in old mail
65 archives. It is generally possible to ignore all but the "user@hostc"
66 part of the address to determine the actual address.
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68 Postmaster.
69 Every site is required to have a user or user alias designated
70 "postmaster" to which problems with the mail system may be addressed.
71 The "postmaster" address is not case sensitive.
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74 /etc/aliases
75 ~/.forward
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78 binmail(1), mail(1), mconnect(1), aliases(5), forward(5), sendmail(8),
79 vrfy(8)
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81 RFC 2822 (Internet Message Format)
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84 This page is part of release 3.53 of the Linux man-pages project. A
85 description of the project, and information about reporting bugs, can
86 be found at http://www.kernel.org/doc/man-pages/.
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904.2 Berkeley Distribution 2004-09-15 MAILADDR(7)