Reverse DNS format question

[Oaktech]

Chaps.

 

Our ISP is being a bit rubbish about our reverse DNS entry for our mail server IP address and asking me to define it. I don't know what it needs to be as I haven't dealt with the outside world in this way before.

 

Do I want it to match our mail delivery subdomain (mail1.leaf.bournemouth.sch.uk), or our email address domain (leaf.bournemouth.sch.uk) address?

[twin--turbo]

the server name will be fine mail1.le.....