By the way, it's "UW", not "WU". We are the University of Washington in Seattle, Washington. That's a different institution from Washington University, which is located far away from us.
To answer your question, Pine uses IMAP for non-message purposes, such as address book and remote configuration. You can't use IMAP to write a file in arbitrary (non-mailbox) format, but it's not all that difficult to teach "vacation" (or whatever) software to read a mailbox-format file. Ideally, you would like it to open the file as a mailbox, and use the last message in it. That way, you can have backup versions.
