I have an announcement list with 45,000 members, when I send an email not
only does it severely overload the server but it also gets blocked from
performing DNS lookups after the first few thousand lookups.
It has been suggested that I set up a caching DNS server but that doesn't
look as easy as it sounds and I already am using bind so I would prefer just
tweaking that installation to do what I need if possible. Looking on the
internet it just isn't clear cut how to do this, especially in a way that
isn't going to mess with my current setup which is a typical Redhat Cpanel
setup hosting a fair amount of sites.
What have other people done in this instance?