Changing my MX Records - Backup Inhouse Mail Server

[weballianz]

Hi,

I want to add an in-house backup mail server.

I go in your Cpanel -> MX Entry -> Change MX Entry -> I want to change for: subdomain.domain.com to: Priority:3 or 15 and my local mail server is: 70.100.12.21

I can't do this because I receive the following Error:

Error fetching zone data for subdomain.domain.com.db's MX

[nicethom]

ther may be an error in the zone file file of your domain please check that