RE: [Exim] checking quota before accepting the message

Greg A. Woods wrote:

> Note this is specific to Cyrus IMAP, but it should be very easy to
adapt
> to any other quota system. It may be more necessary with Cyrus though
> because it's not easy or inexpensive to query Cyrus in any other way
to
> find out the quota usage on every delivery -- that would be insane!
;-)

Speaking of expensive - I ldap-queried our AD domain to reject unknown
users
(exim is our front-end mailer) before forwarding the mail to our
<cough!>
exchange server.
To make a long story short I found it too expensive to do in real-time
(our
fluctuation isn't that big <g>) so I ended up distilling a "good users"
list
every night. Real-time checking is nice but without an intelligent
caching
backend it's usually just a waste of CPU and LAN resources. Additionally
you
give up redundancy (LDAP server dies -> exim can't check recipients ->
loss
of mail).
My two cents...

--
Ben