Athena is reliably on the "Internet".  This network spans the U.S. and
parts of other countries, encompassing many universities, research
institutions, corporations, and governmental institutions.  You can
remotely login with 'telnet' (if you have an account on the remote
machine), transfer files (using 'ftp'), and send mail between Athena
and any host on the Internet.  Currently, the Internet has
domain-based nameservers to handle all of the host names that used to
be in one huge table.  Some top-level domains are EDU, COM, and GOV.
Athena's official name is MIT.EDU.  This means that athena is
under the MIT subdomain of the EDUcational top-level domain.  Your
mailing address is:

	username@MIT.EDU

So, to send mail to someone on the Internet, you need to know his official
mailing address.  It will have a form similar to the above example.

You can also send mail to hosts on the following networks: 
BITNET, and UUCP.

BITNET is a worldwide network connecting mostly DEC VAX systems and
IBM mainframes.  Mail between the Internet and the BITNET may be gated
through MITVMA.MIT.EDU, so outgoing mail to someone on the BITNET
would have this form:

	username%bitnet-host.BITNET@MITVMA.MIT.EDU

Another network is the UUCP network. Many UUCP hosts are also
connected to the Internet, but others are not, instead relying on
periodic transmission of e-mail (using the UUCP protocol) over
modem. Hosts that are connected only to the UUCP network can be
divided into three main categories. First, there are hosts that have
domain names just like Internet hosts. E-mail can be sent to these
hosts just as if they were on the Internet. However, you'll notice
that you cannot, for example, "finger" the host, since the "finger"
protocol isn't provided on the UUCP network.

Second, there are hosts that have no domain names, but are centrally
registered with the UUCP Mapping Project based at Rutgers. E-mail can
be sent using the format

	username%host.UUCP@eddie.mit.edu.

Usually, but not always, hosts that choose not to have domain names are
not as well connected to the network, so you may find that e-mail there is
slow (e.g., over a day to arrive) and sometimes unreliable.

Third, there are hosts that support UUCP mail but aren't generally
known to the outside world, at all. To send mail to such a host, you
need to specify a "path" describing the intermediate hosts that are
involved in relaying mail to it. An example would be:

	relay1!relay2!host!user@EDDIE.MIT.EDU

If someone on such a host wanted you to write to them, they would
probably need to tell you the correct "relay1!relay2!host!user"
portion; it's unlikely that you could determine the correct format on
your own. As in the previous case, mail may be slow and unreliable.


last updated: 8/17/00