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How to Verify that MX Records Do Not Point to the FQDN of an Exchange Server

  • Article
  • 08/08/2014

 

When SMTP queries DNS, it always queries for MX records first. If an internal MX record exists and/or it is incorrectly configured, your internal mail delivery may not work.

Before You Begin

Before you perform the procedure in this topic, read Verifying DNS Design and Configuration

Procedure

To verify that MX records do not point to the FQDN of an Exchange Server

  1. At a command prompt, type nslookup, and then press ENTER.

  2. Type server <IP address>, where IP address is the IP address of your internal DNS server.

  3. Type set q=mx, and then press ENTER.

  4. Type <fqdn>, where fqdn is the fully qualified name of your SMTP virtual server (and your Exchange server), and then press ENTER.

  5. Verify that no MX records exist for your internal server. Your results should look similar to the following:

    > set q=mx
> server1.example.local
example.local
        primary name server = server01.example.local
        responsible mail addr = hostmaster.example.local
        serial  = 6225703
        refresh = 900 (15 mins)
        retry   = 600 (10 mins)
        expire  = 86400 (1 day)
        default TTL = 3600 (1 hour)