The default configuration of pine on PNCE-Unix/Glue is to have pine directly access your mail folders over a distributed filesystem (e.g. AFS). This has the advantage that normal process file access controls can be used to control access, which means you do not need to log in again.
On the downside, this could conceivable cause problems with mail being lost, especially if you run multiple email clients (by multiple clients, I mean both running two different programs, like pine sometimes and Outlook at other times, or even just running two different instances of pine. The latter is bad, the former is worse.) When multiple pine processes are running for the same user, they both want exclusive control over your mail folders, so that they can rewrite them based on what is in memory knowing no changes were done (since they have exclusive control). Pine uses its own file locking mechanism to prevent two processes from thinking they have exclusive access to your files, and that works of the time (this is why you may see pine opening in read-only mode). But file locking is tricky, especially over a distributed file system, and sometimes it does not adequately protect you. With different applications, the likelihood of protection can greatly diminish due to different locking algorithms being used. Having pine access the files directly also means more work for pine, which means you may be more susceptible to subtle bugs in pine.
IMAP is a protocol for accessing mail inside mail folders over the network. It is the recommended access protocol for most graphical user interface email clients (e.g. Outlook, Thunderbird, Netscape, etc.). But pine supports it as well. The actual file accesses, etc., occur on the server side, and therefore can typically do a better job of avoid file locking issues. Also, because just about all non-pine users go through the same interface, any problems/bugs with the IMAP server are typically caught and remedied quickly.
Because it is a network protocol, IMAP requires you to enter your username and password to gain access to your email. The original IMAP protocol passed that information unencrypted over the network, which is bad. Campus uses IMAP encapsulated in SSL to provide encryption for your IMAP session as well.
In summary, the standard direct file access mode of pine is more convenient. But it is also more susceptible to problems, which may result in the loss of emails. If you want your email to be as reliable as possible, you are best off using IMAP and SSL. This is supported by pine as well as most other email clients.
The following instructions are to assist you in converting your pine to use IMAP and SSL, specifically for the Physics Department email server.
cp ~/.pinerc ~/.pinerc.preIMAP
If you have any problems, feel free to contact PCS.