.\" @(#)mailaddr.7 4.2 %G%
mailaddr \- mail addressing description
Mail addresses are based on the ARPANET protocol
listed at the end of this manual page.
These addresses are in the general format
where a domain is a hierarchical dot separated list of subdomains.
is normally interpreted from right to left:
the message should go to the ARPA name tables
(which do not correspond exactly to the physical ARPANET),
then to the Berkeley gateway,
after which it should go to the local host monet.
When the message reaches monet it is delivered to the user ``eric''.
Unlike some other forms of addressing,
this does not imply any routing.
although this address is specified as an ARPA address,
it might travel by an alternate route
if that was more convenient or efficient.
at Berkeley the associated message
would probably go directly to monet over the Ethernet
rather than going via the Berkeley ARPANET gateway.
Under certain circumstances
it may not be necessary to type the entire domain name.
In general anything following the first dot
if it is the same as the domain from which you are sending the message.
since it is the same on both sending and receiving hosts.
Certain other abbreviations may be permitted
at Berkeley ARPANET hosts can be referenced
as long as their names do not conflict
Certain old address formats
are converted to the new format
to provide compatibility with the previous mail system.
to be consistent with the
This is normally converted back to the
before being sent on for compatibility with older UUCP hosts.
The current implementation is not able to route messages
automatically through the UUCP network.
Until that time you must explicitly tell the mail system
which hosts to send your message through
to get to your final destination.
Domain names (i.e., anything after the ``@'' sign)
may be given in any mixture of upper and lower case
with the exception of UUCP hostnames.
Most hosts accept any mixture of case in user names,
with the notable exception of MULTICS sites.
.I Differences with ARPA Protocols.
Although the UNIX addressing scheme
is based on the ARPA mail addressing protocols,
there are some significant differences.
At the time of this writing
domain defined by ARPA is the
This is further restricted to having only one level of host specifier.
the only addresses that ARPA accepts at this time must be in the format
(where ``host'' is one word).
under the ARPA protocols.
these addresses are converted to a different format on output
it may be necessary to route a message
to get it to the final destination.
Normally this routing is done automatically,
but sometimes it is desirable to route the message manually.
An address that shows these relays are termed
<@hosta,@hostb:user@hostc>
This specifies that the message should be sent to hosta,
even if there is a more efficient path
occur frequently on return addresses,
since these are generally augmented by the software
It is generally possible to ignore all but the
part of the address to determine the actual sender.
Every site is required to have a user or user alias
to which problems with the mail system may be addressed.
Messages to CSNET sites can be sent to
``user.host@UDel-Relay''.
The following comments apply only to the Berkeley environment.
Many of the old familiar host names
single character names as used in Berknet
are incompatible with the larger world
of which Berkeley is now a member.
You should notify any correspondents
The old addresses will be rejected as unknown hosts
sometime in the near future.
If you are on a local machine,
yourname@monet.Berkeley.ARPA
However, since most of the world does not have the new software
you will have to give correspondents slightly different addresses.
yourname%monet@Berkeley.ARPA
From UUCP, your address would be:
The Berkeley Computer Center
is in a subdomain of Berkeley.
Messages to the computer center
user%host.CC@Berkeley.ARPA
may be used if the message is sent from inside Berkeley.
are known within the Berkeley domain,
it is likely that this situation will change
with time as both the Computer Science department
and the Computer Center grow.
Hosts on bitnet may be accessed using:
(``group:user1,user2,user3;'')
is not supported except in the special case of
because of a conflict with old berknet-style addresses.
Standard for the Format of Arpa Internet Text Messages,