We run 2 dedicated Windows 2008 R2 servers from our ISP. Yesterday for no reason at all 1 of our servers stopped sending email.
The server uses MailEnable for sending outgoing SMTP emails only. IE. There are no incoming email traffic at all. The emails are all being held in the outbound SMTP queue, and checking the debug logs for MailEnable I'm getting lots messages like this:
> SMTP Connection DNS Server could not resolve domain name (exampleDomain.com) in a timely fashion. Check DNS Server settings.
If I do an nslookup I get the following:
Default Server: UnKnown Address: 220.127.116.11
The IP 18.104.22.168 is one of our ISP DNS servers.
If I do ipconfig /all I see 2 DNS servers list, the one above and 22.214.171.124.
In DNS Manager if I try to add my server, or either of the DNS servers I just keep getting the message
The server is unavailable. Would you like to add it anyway?
I'm not sure where to go from here. We have not made any changes to our servers or DNS records. Our ISP wants to wash their hands of the whole situation, claiming, dedicated servers are the responsibility of the client.
I would appreciate any help at all with this problem.
Thanks in advance.