Information Technology Division
Services:
Rules and Procedures


Campus email delivery explained


Audience: Campus

Service Type:
Electronic Mail Services (Email)

Service Name:
ITD Email Services

Brief description of service:
ITD provides SMTP (Simple Mail Transport Protocol), and IMAP (Internet Message Access Protocol) email services to the NC State community.

ITD makes every effort to ensure quick, reliable email transport and delivery, but sometimes delays can and must occur, and any given email message may take several hours or more to reach its destination. This document explains how email is delivered and describes the quality of email service the campus community can reasonably expect.

Email works on what is referred to as a "store and forward" system. For example, apiece of email starts out on your machine, then travels from one server to another until it finally arrives at the server holding the recipient's mailbox. Each intermediate server stores the message locally until it is forwarded to the next server in line; the email resides on only one server at a time.

As often happens in any collection of networked systems, interruptions can occur. The network could be down in one place, or a server could be broken or overloaded to a point where it can't handle any more mail. Knowing that these things can and do happen, email delivery has a built-in method of compensating: Email that fails to get forwarded stays on the sending server and delivery gets retried every 30 minutes for three days.

Designed into the email delivery process is a mechanism whereby the receiving server can tell the sending server "I'm not taking mail right now, try back later." Many popular email servers (including Hotmail, AOL, Yahoo, and us) do this all the time when large batches of email come in, so they don't get overloaded trying to handle too much email at one time.

It is impossible to guarantee immediate email delivery. It's explicitly built into the system and considered perfectly acceptable for the email to be delayed for some period of time. Only if the mail cannot be delivered after three days is it considered an error.

This point is important enough to repeat: It is impossible to guarantee immediate mail delivery. If email can't be delivered for some period of time, the protocol accounts for those delays and will attempt retries at periodic intervals.

Clients eligible for service:
All NC State students, faculty and staff

Type of use:
University business or personal use

Cost:
There is no additional charge for using the campus SMTP email relays or IMAP servers.

To obtain service:
ITD automatically generates Unity computing accounts and email services for all NC State students, faculty and staff. To use the NCSU Webmail client, log in to https://webmail.ncsu.edu/. For further information visit the Computing Essentials website (http://www.ncsu.edu/it/essentials/) or contact the NC State Help Desk at http://help.ncsu.edu or
help@ncsu.edu

Rules of use:
All NC State computer and network resources are governed by Administrative Regulations - Computer Use

 

Submitted by: tkl
Last modified:
December 14 , 2005,jd

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