I'm having some difficulty with my pop3/smtp services in Win2003 Server. Here's the setup: Server1 acting as primary domain controller and primary DNS, WINS. Server 2 as secondary WINS and Server 3 on WINS replication via VPN. Server 1 also acts as my mail server using Merak IceWarp Mail Server. Herein is the problem and I don't know where to start to fix it:
My primary DNS server (server 1) has the name server1.domainname.com and has pop3 and smtp running. However, my WINS clients on Server 3 seem to be having trouble finding the pop3 and smtp server name using Outlook 2003. For a majority of the time, I can use server1.domainname.com as my pop3 and smtp server name and Outlook respons fine. However, out of the blue it seems, the pop3 name stops responding and I have to change the pop3 settings to mail.domainname.com. I have no clue what is happening or what causes this.
Extra info: my primary DNS IP is internal 10.1.1.12. My secondary DNS is my ISP 18.104.22.168. I have an MX record (server1.domainname.com) and Host (A) record (10.1.1.12) on Server 1. Server 3 is a remote location connecting via VPN to central office. Same ISP for both offices.
I hope this is plenty of information. Thanks in advance for all help!