So this is a step in the right direction. But still far less than
optimal. The read/write lock contention on mbox is unnecessarily eating
up system resources (mainly memory), and causing unnecessary delivery
delays to the mailbox. You should really start looking at migrating to
maildir. It's not that difficult (though maybe more so with 1.0.7) if
you don't have a ton of mailboxes, and especially with POP since the
mailboxes typically wont be holding much mail to migrate. How many do
you have?
There's around four hundred mail boxes or so. Some used more
intensively than others.
Our server is with Rackspace, and RHEL5 is the OS they offered us as an
upgrade path from RHEL4. So they're getting the support from Red Hat
and we're getting the support from Rackspace.
The plot thickens again. You're using a rented server. Sigh...
This entire thread could have been greatly shortened, saving all of us
much time, if you'd have given all these details up front.
Is this a cloud server (shared host), or a dedicated server?
It's a dedicated server
FWIW, you don't have RHEL5, but CentOS 5. Hosting companies don't pay
for RHEL licenses for 10s of thousands of hosts.
It's RHEL5:
$cat /etc/issue
Red Hat Enterprise Linux Server release 5.8 (Tikanga)
The cost of the license is included in our contract.
I have a few salient recommendations for you:
1. Migrate to maildir. It is far more appropriate for a POP workload.
Yes, this will be our next course of action
2. Switch to a hosting provider that offers much more recent software.
We can upgrade the software if we wish, but will no longer get full
support from Rackspace if we do this.
3. Or, get a colo server so you can use whatever software you wish.
We can install whatever software we wish at the moment, but see the
point above.
Finally, if this email service you're providing isn't all that critical
to you or your organization, simply prod along as you have been,
fighting these problems frequently along the way.
It's kind of working ok now but we will go with your recommendation of
switching to maildir when we have time. Thanks for your help
