we've got a strange DNS problem. To give 2 examples:
* Our mail relay server sometimes can't deliver mails. I've been investigating this and it turns out it finds wrong or incomple MX records. The same goes for
* And the same with our proxy server, sometimes some websites are not reachable ("Website Not Found") not because the website address is incorrect, but because our DNS server didn't find the correct records!
Our DNS server (Windows Server 2003 R2 SP2) has the default roothints. When this occurs I have to do a flushdns and restart the DNS Server Service. After that it finds the correct records and the mails get out, websites load again.
What could be the cause of this and the possible resolution?
I've been thinking to put in a DNS forwarders for all external addresses to our network provider, but I'd rather not rely on that (in case we ever change, they change their DNS config, ...)
thanks in advance for all advice