Electronic Mail E-mail POP mail server IMAP mail transport server is a system for sending messages or files to the accounts of other computer users Senders and recipients may be on the same or different computer system like regular postal mail, every user on the network has a private mailbox POP mail server IMAP mail transport server

E-mail URL E-mail URL Header Body has the format “mailto:user-address” Hohly@cerritos.edu Woolever@cerritos.edu President@whitehouse.gov lets you send messages to a particular person Header to whom the message is sent who the message is from what the subject is Body is the text of the message

E-mail - commercial services America On-line <user>@aol.com Applelink <id>@applelink.apple.com BITNET <user>@<node>.bitnet CompuServ 71234.567@compuserv.com MCIMail 123456@mcimail.com Netcom <user>@ix.netcom.com Microsoft Network <user>@MSN.com

Pros and Cons gets a message from one point to another very quickly cheaper than a telephone for instant long-distance communication the sender can send it when it’s convenient recipients can read it when it’s convenient no matter how quick a message may arrive, it may be late if the receiver fails to check the e-mail on a regular basis easy to distribute messages to multiple receivers because it is easy, junk mail is sent to a large number of people, chain letters can flood the network security is low in e-mail communication careless comments can lead to misunderstanding

Guidelines Never send e-mail that you wouldn’t want to become public keep length of lines short don’t use abusive, harassing or bigoted words Use both upper and lowercase characters Be careful with sarcasm or jokes Read the message before sending When responding to message with multiple recipients, be very careful to whom you are responding

Email on Cerritos Alpha logon At the $ prompt, type EMAIL (not case sensitive in Cerritos campus environment) Type “dir newmail” to check for new mails (unread mails) Type “1” to read mail #1, “2” to read mail #2 Type “dir mail” to look at read mails (old mail) Type “reply” or “forward” to reply or forward the message you are reading Type “delete 1-6” to delete the first 6 mails (be careful which folder you are in, the mail folder or the newmail folder)

Email address Username@hostname.domainname Top level domains - North America (organizational) Top level domains - Country (geographical)

Organizational domain name If geographic location is not specified, it is assumed to be the United States COM Commercial organizations EDU Educational and research institutions GOV Government agencies MIL Military agencies NET Major network support centers ORG Other organizations INT International organization

Geographical domain name AQ Antarctic AR Argentina AT Austria AU Australia BR Brazil CA Canada CH Switzerland CL Chile DE Germany ES Spain FR France HK Hong Kong KR Korea MX Mexico PR Puerto Rico PT Portugal SG Singapore TW Taiwan UK United Kingdom US United States VE Venezuela ZA South Africa

Domain name and IP address unique range of address is assigned to network site one address for each device on the network each address is a number called an ‘Internet Protocol’ (IP) address a series of four number separated by periods (dots) e.g. 158.104.1.1 IP address is hard to remember by human Domain name jupiter.willamette.edu is the domain name for IP address 158.104.1.1

Domain name and IP address michael.ai.mit.edu the Interent host michael is in the domain called ai, which is in the domain mit which is an educational institution (edu) domain names are divided into various levels last word in the domain name is the top-level domain, which can be geographic location/countries or organizational in North America

IP (Internet Protocol) address 4 numbers separated by periods (“dots”) 192.74.137.5 = world.std.com 198.188.96.9 = alpha1.cerritos.edu Domain naming machine.subdomain.organization.domain fred.mfg-div.galacto.com computer subdomain domain Specific ................. General

Internet Address examples Domain examples msc.cerritos.edu gold.cerritos.edu calstate.edu lbcc.cc.ca.us jabber.wock.com flack.cs.laputa.edu dims.demon.co.uk north-high.menlo.k12.ca.us

Internet User address examples user@domain alice@jabber.wock.com ralph_r@topdeck.pinafore.nav.uk fred@bigfoot.kimball.ma.us president@whitehouse.gov vice.president@whitehouse.gov

Domain name The second to last word in domain name is descriptive reference e.g.. stjude.edu educational institution name St. Jude’s nwnet.net network service provider called NWNet apple.com a company called Apple jupiter.willamette.edu mercury.willamette.edu are both computers in the Willamette University network.