Question: Are there any email programs that work offline?
Answer: All stand alone email programs work offline. You only need to go online to actually download the emails.
You can of course configure some email programs to leave the emails on the server and not download them which limits you to using the program while online but the only email program that works that way by default is the one built into AOL where you have to change the settings to get the regular email program behaviour of downloading the emails to the local computer.
Also when using the program offline you wont see any linked images but if you have the security set properly you wont see linked images in emails even when you are online.
The only email programs that don't work offline are web pages that provide a web mail facility. As these operate via a web site rather than as a separate program on your own computer you need to be online in order to access the site where the mail is stored. Many web mail services provide the information necessary to configure a stand alone email program to be able to access the same emails as on that web mail service and if you set that up with it configured to download copies of the emails then you would be able to use that to access the downloaded emails while not online.
This article written by Stephen Chapman, Felgall Pty Ltd.