CentOS 5.x | SendMail
I have a SendMail server configured to smarthost to a FQDN (for the purpose of discussion, let's call it group.example.com). group.example.com originally had two A records associated with it: 188.8.131.52 and 184.108.40.206. Under this scenario, it would usually send email evenly to both servers.
I've recently added a third A record to the same FQDN: 220.127.116.11. What's strange is that I'm not seeing any traffic ever going to 18.104.22.168
My questions are:
1) Does SendMail cache DNS records? If so, how can this be flushed?
2) How does sendmail (or the native dns resolver if it's just CentOS) evaluate which of the 3 A records to use?