I dont completely understand the IMAP/POP3 process. I have IMAP/POP3 installed properly. I can telnet to both the 143 and 110 ports. If I use a client to connect via IMAP, does IMAP automatically just access the default directory for the login user in question and process mail from the mbox? Does this work the same for POP3 but POP3 actually pull the entire message down without leaving it on the server?

Should Microsoft Outlook be able to handle the client portion?

Thanks for any responses.

Okay. From my limited experience, this is how I understand it (if someone knows better, please correct me):

IMAP maps whatever you do in your email client (Outlook, Thunderbird, Evolution, etc.) to whatever's going on in the email server. For example, if you move a message from your Inbox to a folder called Saved Messages, the message on the email server will actually move from the Inbox to Saved Messages. It also means that none of the messages actually exist on your computer's hard drive (though, there's usually an option to have offline use of certain folders if you want that).

POP3 takes little snapshots of what's going on in the email server and downloads the messages to your hard drive. You usually have the choice of downloading them completely to your hard drive or downloading them and keeping a copy on the original server.

The advantage of IMAP is that you can check it anywhere (home, work, school, a friend's house), and your email will be exactly the way you left it last time. IMAP's a bit slow, though, since it always has to sync with the server.

The advantage of POP3 is that it's fast, and you have easy access to your messages on the hard drive even if you're not connected to the internet.

aysiu has the right idea. As to your question about mbox, it depends on the IMAP server. Usually the best ones set up a maildir folder in your home directory, and mail is delivered to that, but you can usually configure them to work with the mbox format as well.

POP3 clients by default usually retrieve the message and then delete it, but you can configure most clients to skip the delete step. The only thing is, there is no sync between different clients - if you check your mail from three places, you have to download each piece of mail three times. With IMAP, the client only downloads the headers until you request a specific message. POP3 has support for only downloading the first 'n' lines of a message, but I've never used a client that did this, probably because you can never tell how long the header section will be.

Outlook will work fine for both POP3 and IMAP connections, as will Outlook Express.