Re: [Exim] using exim w/ more than 65000 users

>     This is what we did. A database or (in our case) a big LDAP directory.
> The downside, as Yann said, is that you need some big iron to put it on,
> but if you're running an O(100K users) system then that's going to be
> the case anyway, neh? :o)

Nice to see that others use LDAP, too. Big iron, well, what's big iron
these days any more? All my nodes are Pentium III PCs with 19" case,
512 MB ECC RAM and either two 18 GB HDs or (for the mailboxes and the
outgoing queues) SCSI-to-SCSI RAIDs. The system is scalable (multiple
MX nodes, mbox nodes and outgoing queue nodes) and works fine for over
half a million mailboxes.

IMHO, the configuration can be understood easily by anybody who read
the great Exim manual, but I am sure some people will disagree. ;)

If you use OpenLDAP, then do not use a local replica server or at least
check its impact. I know that said it was an advantage for me, but
things have changed about two months ago. By now the mail traffic seems
to dominate the buffer cache in a way that the ldap replica server causes
awful disk traffic (many small requests), which slows down everything.
Putting the replica on a different machine all on its own speeds up both
Exim and LDAP a lot.

Michael