CPSC 3600 - DAY 8
FEBRUARY 6, 2017

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INTERNET APPLICATIONS (PART 2)
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	.Simple Mail Transfer Protocol:
		.Follows a stream paradigm,
		.Uses textual control messages
		.Only transfers plain text messages
		.Allows a sender to specify recipients' names and check names
		.Sends one copy of a given message.
	.Special purpose email interface application
		.Advantages
			.Downloading entire mailbox to local machine
			.Ability to create drafts without internet

	.Mail Access Protocol
		.POP3 - Post Office Protocol Version 3
		.IMAP - Internet Mail Access Protocol
	.Email Representation Standards
		.Request for Comments 2822 Mail Message Format
			.Header Section
			.Blank line
			.Body
		.Multi-purpose Internet Mail Extensions (MIME)
			.Header
				.MIME-Version(typically 1.0)
				.Content-type
				.Content Disposition
				.Content-Transfer-Encoding
			.Body

			.MIME builds off of SMTP, meaning it can transfer
			non-text data in a message.
	.Domain Name System
		.Maps human-readable symbolic names to computer addresses
		.Uses by browsers, mail software and most other internet apps
		.names are hierarchial
	.Caching in DNS Servers
		.Spatial: which states that a user will tend to look up names
		of local computers over names of remote computers.
		.Temporal: states that a user will tend to look up the same 
		domain names.
	.Each entry of DNS consists of three parts:
		Domain Name: mentioned before
		Record Type
		Value

	.Example Record types
		.MX - Mail exchange, connects to the email servers
		.TXT - This type provides text information outside your domain
		.CNAME - Canonical Name Record, links domain names with alias
		it may have.
		.A - Address, links domain to an ip address