mailaddr(7) [netbsd man page]
MAILADDR(7) BSD Miscellaneous Information Manual MAILADDR(7) NAME
mailaddr -- mail addressing description DESCRIPTION
Mail addresses are based on the Internet protocol listed at the end of this manual page. These addresses are in the general format user@domain where a domain is a hierarchical dot separated list of subdomains. For example, a valid address is: eric@CS.Berkeley.EDU Unlike some other (now obsolete) forms of addressing, domains do not imply any routing, or the existence of a particular host. Simply because mail may be sent to ``user@somedomain.com'' does not imply that there is any actual host named ``somedomain.com'', and does not imply a particular routing of the message. Routing is performed by Mail Transport Agents, such as postfix(1), based on policies set in the MTA's configuration. Abbreviation Under certain circumstances it may not be necessary to type the entire domain name. In general, anything following the first dot may be omitted if it is the same as the domain from which you are sending the message. For example, a user on ``calder.berkeley.edu'' could send to ``eric@CS'' without adding the ``berkeley.edu'' since it is the same on both sending and receiving hosts. Whether abbreviation is permitted depends on how your site is configured. Case Distinctions Domain names (i.e., anything after the ``@'' sign) may be given in any mixture of upper and lower case. Most hosts accept any combination of case in user names, although there are exceptions. Postmaster Every site is required to have a user or user alias designated ``postmaster'' to which problems with the mail system may be addressed, for example: postmaster@CS.Berkeley.EDU Obsolete Formats Certain old address formats, such as UUCP ``bang path'' addresses, explicitly routed internet addresses (so-called ``route-addrs'' and the ``percent hack'') and others have been used historically. All these addressing formats are now considered obsolete, and should no longer be used. To some extent, MTAs attempt to provide backward compatibility for these addressing forms, but in practice many of them no longer work. Users should always use standard Internet style addresses. SEE ALSO
mail(1) D. H. Crocker, Standard for the Format of Arpa Internet Text Messages, RFC, 822, August 1982. HISTORY
mailaddr appeared in 4.2BSD. BUGS
The RFC 822 group syntax (``group:user1,user2,user3;'') is not supported except in the special case of ``group:;'' because of a conflict with old berknet-style addresses, not that anyone cares about either berknet or group syntax style addresses any longer. BSD
June 16, 1998 BSD
Check Out this Related Man Page
MAILADDR(7) Linux User's Manual MAILADDR(7) NAME
mailaddr - mail addressing description DESCRIPTION
This manual page gives a brief introduction to SMTP mail addresses, as used on the Internet. These addresses are in the general format user@domain where a domain is a hierarchical dot-separated list of subdomains. These examples are valid forms of the same address: eric@monet.berkeley.edu Eric Allman <eric@monet.berkeley.edu> eric@monet.berkeley.edu (Eric Allman) The domain part ("monet.berkeley.edu") 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 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: "surname/admd=telemail/c=us/o=hp/prmd=hp"@some.where USER%SOMETHING@some.where machine!machine!name@some.where I2461572@some.where (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 "", for example, if it contains ".": "Eric P. Allman" <eric@monet.berkeley.edu> Abbreviation. Many mail systems let users abbreviate the domain name. For instance, users at berkeley.edu 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. 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: <@hosta,@hostb:user@hostc> 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. 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. FILES
/etc/aliases ~/.forward SEE ALSO
binmail(1), mail(1), mconnect(1), aliases(5), forward(5), sendmail(8), vrfy(8) RFC 2822 (Internet Message Format) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 4.2 Berkeley Distribution 2004-09-15 MAILADDR(7)