When we moved our post office offsite many months ago, I set up user's
desktop clients to use caching mode, paying attention only to its
smarter use of limited bandwidth and the ability to work with mail even
without a live connection.

Today while investigating a mailbox size limit question I discovered
something in the documentation that horrified me: "as you employ disk
space management processes in the post office and reduce the size of
users’ Online mailboxes, more and more of the users’ mailbox items exist
only in their Caching mailboxes."

I don't want that to happen! I thought caching would just keep the
local mailbox in sync with the online one. I would be skinned alive if
a user lost an important message to this limitation, or needed to use
the online mailbox (away from desk or whatever) and couldn't find a
message that was only in the cache.

So, I would like to know this: if a user keeps the caching mailbox under
the online size limit ("voluntarily" - i.e., without my setting and
enforcing size limit on cache), will all messages be present in both modes?

If I apply the size limit to caching mailboxes, will that ensure that
all messages are kept in sync between online and cache?