What is it?

IMAP is the E-mail protocol we use on Campus. Our E-mail server is configured such that IMAP compliant E-mail clients can access our server.

POP3 is another E-mail protocol that we are currently phasing out. We DO have a POP3 server but it only services users with existing POP3 clients such as Eudora and Pegasus. No additional POP3 users will be granted access. If users had an email account in the 1996 school year, or before, then they will have an account on the POP3 server. This can be checked by looking up their info on the mailserver. If they have a POP3 account, then it will say "POPUSER" in their info. The POP3 server for JMU is 'popgw.jmu.edu'.

What is the difference between these two protocols? POP3 is an older protocol in which messages are stored on the mail server, until retrival, when they are downloaded to the user's computer. This requires relatively less storeage requirements on the mailserver, but has one disadvantage. If users go to another computer to check their mail, then they will not be able to access any of their other messages, because those messages reside on another computer. Also, any messages they recieve at that computer will remain on that computer. POP3 is a good protocol to use if all the users will be checking their email from one location. But if the users will be roaming, and need to access their account from different locations, then another kind of protocol must be used.

This is where IMAP comes in. With IMAP, messages are not downloaded locally, but rather kept on the mailserver. All operations on messages are performed on the server. This way, no matter where a user is, they will always have access to their email, providing they have access to an IMAP email client. This protocol requires much more storage space on the server, and also makes necessary the use of disk quotas for users. Each user is only alotted a certain ammount of space on the server. If these quotas were not set, then one user could theoretically jam up the entire system.