Are you actually moving your DNS provider as well, or just the server?
In either case unless you have a large number of entries you don't need to look at the old one, just provide the new details to whoever provides your DNS.
The information that is needed are the MX entries (which need to give fully qualified domain names for your mail server), and A records (e.g. for www, and if email is provided on your own server rather than your ISPs mail server a mail A record) with the IP address of your new web server.
The rest of the details (SOA header etc.) will be created by your DNS provider.
You can check your current details using the dig command
Code:
dig mx yourdomain.com
(will show current mail settings)
Code:
dig a www.yourdomain.com
(will show A record)
- repeat for any other subdomains
e.g.
dig a mail.yourdomain.com (if using own mail server)