Some Mail Acronyms
- BITNET
- Because It's Time NETwork. Older, EBCDIC-based network for
communications still used in some circles (such as on the UCS VAX
cluster.) Nobody in the CS department uses it, but on occasion you
may send mail to someone on it through a gateway. See also the jargon
definition.
- Bounce
- To return undeliverable mail to sender, just as is done with real
mail. Just as with real mail, there is some work involved with taking
the returned message and re-sending it to the correct address;
however, unlike paper mail, there is no need for electronic mail to
bounce this way; it's just that most MTAs
are too dumb to do it well.
- ESMTP
- Extended Simple Mail Transfer Protocol. Proposed extensions to SMTP for things like maximum message length
and allowing content wider than 7 bits. Related to the MIME spec. Not yet widely used. The core of the
spec is in RFC 1425
and more is in RFC 1426
and RFC 1427.
- Forward
- To enclose a mail message within another message according to some
specification (such as RFC 934 or
MIME.) Forwarding involves ethical
questions as well as technical ones; forwarding personal mail can, in
some cases, be rude or even illegal.
- FQDN
- Fully Qualified Domain Name. The full hostname of a machine
including all domains it resides in; e.g.
silver.ucs.indiana.edu,
moose.cs.indiana.edu.
- Gateway
- Central service for translation of Email messages (or, more
generally, any sort of information) from one delivery protocol to
another. For example, the CS department runs a mail-news gateway (for
local users) that allows posting by mailing to the newsgroup name. If
you send mail to someone on BITNET, a
gateway will move the message from the Internet (over SMTP) into BITNET, translating one format into the
other as needed.
- Hostile MTA
- An MTA which can modify messages
passing through it in certain nonstandard ways (e.g. delete trailing
whitespace, convert tabs to spaces or vice-versa, etc.) While such
transformations are usually well-intentioned ``optimizations,'' they
can cause things like message integrity checking or encoded contents
to be damaged. Successful encodings must work around them; MIME includes a few ways to do this.
- IMAP
- Interactive Mail Access Protocol, a more sophisticated version of
POP which adds more mailbox capabilities.
Defined in RFC 1203.
- Mailbox
- Location (typically file) in which incoming mail is stored until
the MUA retrieves it. Also sometimes called
spool file or maildrop; on most UNIX systems it is named
/var/spool/mail/<username>.
- MIME
- Multipurpose Internet Mail Extensions. A standard for adding new
capabilities to Internet mail; more
info on MIME is available.
- MTA
- Mail Transport Agent. The software (here,
sendmail(8)) which handles moving and
delivering messages, and which normally doesn't deal with users. Even
though sendmail is somewhat difficult to configure and use, nobody has
created a generally accepted replacement; some note that it seems as
difficult to get rid of as real postal employees. :-) An MTA that
takes liberties with modifying message contents is termed a hostile MTA.
- MUA
- Mail User Agent. Sometimes referenced as just UA. Describes the
software (e.g. Elm, MH, Mush) that interacts with the user.
- PEM
- Privacy-Enhanced Mail. Relatively new standard for Email security
using cryptographic techniques for authentication and privacy of
messages. Primarily defined in RFC 1421,
1422, 1423 and
1424.
One somewhat popular attempt at an implementation is RIPEM.
- POP
- Post Office Protocol. Specification for remote access to
mailboxes; typically used for an MUA to
receive mail from a mailbox on a
machine it does not share a filesystem with. Not much used here in
CS, where all mailbox disks are NFS mounted all over the place.
Defined in RFC 1460.
- RFC
822
- Request For
Comments 822. The document which originally specified the format
for Internet email messages. It is the most influential and enduring
(and cited) RFC.
- SMTP
- Simple Mail Transfer Protocol. Standard protocol for delivering
mail across the Internet; originally specified in RFC 821.
- UUCP
- Unix-to-Unix CoPy. A protocol for file and message
transfer, typically used over dialup connections for machines not
directly connected to a network. Its importance has waned as direct
Internet connections become more common, but it's still used.