E-Mail Terminology and Acronyms

ASCII: an acronym standing for "American Standard Code for Information Interchange". ASCII is the code that translates letters, numbers, punctuation, and other text symbols into a numerical code that computers can understand. When a computer guy says "I need the file in ASCII" they mean that they need the information in plain text -- no fonts, or anything fancy. Programs like Microsoft Word that give you font/bold/underline capabilities do not store their data in ASCII. However, Word can store a document in ASCII or "plain text" when this option is selected. Word will warn you that all formatting will be lost. Primitive editors like Wordpad and the UNIX vi editor speak only ASCII.

DNS: Domain Name System. An Internet service that translates domain names and computer names (e.g., "mail-hub.colby.edu") into IP numbers (e.g., "137.146.210.56") that computers can understand. People remember names well and numbers poorly. Machines need numbers to get their job done. So DNS translates human readable names into the numbers that computers need. Think of DNS as the cosmic phone book of the Internet. For a more detailed explanation of how DNS works, click here.

E-mail forward: An e-mail forward silently forwards all messages bound for a Colby address on to another address elsewhere. No other processing of the message is done -- it is not checked for spam or viruses, nor is a copy saved on Colby's mail server. The sender is unaware that his message went on to an undisclosed location. ITS Guideslines state that a forward will only be used temporarily for a person who will "soon" return to Colby. A forward will not be set for an indefinite period of time. A forward will NOT be used for a person who has left Colby permanently -- an e-mail redirect is used instead.

E-mail redirect: An e-mail redirect advertises the fact that a person formerly at Colby has moved elsewhere, and that his e-mail address has changed as a result. A redirect bounces a message back to the sender telling them that the person has moved, no longer has a Colby e-mail address, and that they can be reached at an alternate e-mail address of that person's choosing. It also notes that the original message will have to be retransmitted to the new address for the recipient to see it. ITS Guidelines state that people who have left Colby (graduated, new job elsewhere) may only have a redirect, not an e-mail forward.

FTP: File Transfer Protocol. A method of doing bulk file transfers, at high speed, between computers. There are many ftp clients for Windows (wsftp) and Mac (fugu), including many that support SSH. Contact ITS support for more information on ftp clients for your computer. E-mail is not the way to do bulk file transfers!

IMAP: Internet Message Access Protocol. Used instead of POP. For a discussion of POP versus IMAP, click here.

INBOX: Another name for your mailbox on Colby's mail server. This is where an incoming message ends up after the MTA has done its job and procmail has delivered it locally on the mail server. Both POP and IMAP look at the contents of your INBOX when they check for new e-mail. Do not leave important messages in your INBOX for long periods of time, or the Mail Expiry Agent will delete them!

IP number: IP stands for "Internet Protocol." The IP number of a computer is the numeric address of a computer on the Internet. DNS converts human readable computer names and domain names into IP numbers so that computers can find each other. IP numbers are of the form X.X.X.X, where X is an integer between 0 and 255. All IP numbers in the Colby domain start with 137.146.

Mail Expiry Agent: A process that runs periodically on the mail server to delete e-mail messages from your INBOX, according to Colby-defined policies. The purpose of the Mail Expiry Agent to reduce mailbox bloat, disk usage, and wasted CPU cycles.

MTA: Mail Transfer Agent. This is geek-speak for the mail processing software that runs on a mail server -- a machine that speaks SMTP with other mail servers. Colby uses sendmail as its MTA. Mail servers have the job of routing e-mail to remote destinations, holding e-mail that cannot be delivered (either locally or remotely), rejecting e-mail for various reasons (incorrect protocol or filtering), and returning undelivered e-mail. Believe it or not, MTA’s do not have the job of delivering local e-mail to your INBOX. The MTA hands local-delivery e-mail to another process for this final step. Colby uses procmail for local delivery to your INBOX.

MUA: Mail User Agent. Geek-speak for an e-mail client that a human would care to use, like Eudora, Pine, or Thunderbird. MUAs not only speak SMTP to transfer outbound e-mail to an MTA, but they also speak POP and/or IMAP in order to retrieve inbound e-mail from a mail server. Most modern MUAs offer numerous other amenities, like the ability to sort and store e-mail in different folders, handle attachments, automatically check for new e-mail, and filter messages.

Megabyte: Slightly more than one million bytes of data, abbreviated as "MB". One MB is technically 1024 x 1024 bytes, since 1024 is a power of two (1024 bytes is one kilobyte or one KB). One byte can hold one ASCII character. One Gigabyte or GB is 1024 MB, and so on.

Nigerian 419 spam: A type of financial scam spam that is very hard to filter because it looks so much like legitimate e-mail. For more information, see the notice at the US Secret Service website.

Phishing: Like Nigerian 419 spam, another type of scam spam sent to you with the purpose of attempting to trick you into revealing personal information that can be used to (a)clean out your bank/brokerage/paypal account, (b) abuse your credit card, (c) commit identity theft. The e-mail usually contains a weblink to a phony site that looks like your real bank's webpage. This website wants you to enter in personal information like your name, Social Security number, bank account numbers, mother’s maiden name, etc. Don't fall for this scam!

POP: Post Office Protocol. Used instead of IMAP. For a discussion on which is better for you, click here.

RBL: Realtime BlackHole List. A list of IP numbers that mailer software can use to block spam. If a number appears in the list, ALL e-mail from that computer is rejected. RBLs are dynamic and use DNS software to allow IP numbers to be blocked in "real time" and to have this block information propagate to sites that use the RBL for spam filtering.

SMTP: Simple Mail Transfer Protocol. The protocol that two MTA’s speak to each other to transfer mail. E-mail clients (MUA's) also speak this protocol to send e-mail from the client to an MTA, thence on to the world.

Spam: Unwanted junk e-mail. Most spam is sent by scam artistes and criminal gangs with the purpose of selling you phony products (like black market Viagra) or relieving you of your money and your identity. The vast majority of spam is sent from hacked machines (known as “zombies”) that the criminals have reconfigured to serve as mail servers. Also see phishing.

SSH: Secure Shell and related utilities, such as a secure form of FTP (sftp). The SSH utilities use SSL to encrypt network sessions for secure logins (ssh) and secure file transfers (sftp and scp). OpenSSH is one well-known and open source version of SSH.

SSL: Secure Socket Layer. A software component that SMTP, POP,and IMAP can use to encrypt e-mail traffic. Encryption prevents snoopers on the Internet from reading your messages as they travel from source to destination. Does not prevent snooping once the message has been delivered, for that you should encrypt your message before e-mailing it.

URL: Uniform Resource Locator. The "address" for a webpage that usually starts with http://, e.g. http://www.colby.edu