Typing in password multiple times AND ampersands in mailbox names

[Tim Wilson <tdw@symbionics.co.uk>]

I'm quite a new user of nnimap, and I'm finding it an excellent way of
reading mailing lists that accumulate in folders on the company's
MS Exchange server.

My first question is: Emacs asks me for my IMAP password once for
every group I have subscribed to using nnimap.  As I'm using nnimap
for more and more, I'm getting tired of typing in my password again
and again!  Does anyone have suggestions about how to avoid this?

My second question is: I am unable to make nnimap read any mailbox (aka
folder) that has an ampersand ('&') character in its name.
Renaming the mailbox (via Outlook/Exchange) to remove the ampersand
solves the problem.  Any suggestions?

I use emacs 20.3.1 with the following setup in my .gnus:

(setq load-path
      (cons (expand-file-name "~/share/emacs/site-lisp/nnimap-0.130")
	    load-path))
(require 'nnimap)

(setq gnus-secondary-select-methods
      '((nnimap "exchange"
		(nnimap-address "[deleted]")
		(nnimap-expunge-on-close 'ask)
		(nnimap-list-pattern ("Inbox" "People/*" "Subjects/*")))))

Thanks in advance,

Tim