I know this is a little off-topic, and I know there is has been some discussion touching on it.Which IMAP serever does everyone like? It sees that the one that comes with pine is fine according to most. Is there a better one?
You probably want to ask this on the comp.mail.imap newsgroup.
I'm using UW-IMAP, as it comes with Red Hat. Others include Cyrus and Courier. The author of the IMAP RFC is less than satisfied with COurier due to some shortcuts that Courier takes with the standard.
As important as choice of server is choice of client. I've tried a few and so far my favorite is Mulberry (http://www.cyrusoft.com/), a commercial product. Versions are available for Win32, Linux/Solaris, and Mac OSX. Development is very active. Features are often hard to find because the program is so configurable. An archive of its discussion list is available as an anonymous IMAP mail store.
Eudora's IMAP handling isn't very advanced. (See my recent posts on comp.mail.eudora.ms-windows.) Ximian Evolution is pretty good but it's only available for Linux. Mozilla's IMAP is still a bit primitive, for instance lacking the ability to see deep server mailbox hierarchies.
