RE: [Exim] checking quota before accepting the message

On Sat, 2004-08-07 at 21:34 +0200, Hochstrasser Benedikt wrote:
> 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.

(is it possible for you to fix your e-mail client to keep References
intact, and to do a little more sensible word wrap? I undid the word
wrap below.)

> 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).

the LDAP server is commonly a critical resource, if you have an LDAP
service, it is commonly used for authentication in all kinds of systems.
LDAP is also relatively easy to replicate. as such, it simply shouldn't
be acceptable that a single server dying brings down the service.

anyway, a failed LDAP server should only lead to deferred delivery, not
loss of e-mail.
--
Kjetil T.