"Karl G. Ulbrich" cogently stated:
If the goal is mail-in content, I'm not sure I understand IMAP to be anything approaching what you want: IMAP doesn't ACCEPT messages, at least not any of the IMAP servers I've seen, it serves messages up to clients (one of which could be Zope, like WorldPilot does).
I think you're right. I thought about this for a while, and realized what I want is for Zope to publish imap like it does webdav &c.
MailMan supports external archivers (how, I don't know, just saw it mentioned), and with the right archiver plugged in, that would give you the capability to archive email lists however you wanted.
This is exactly what (personally) I want to do: http://www.zope.org/Members/mindlace/MailZopeMan [snip awesome reference] ~ethan