Deactivate mail service?

Just curious what the significance/consequences of doing this (deactivating mail service) would be on any sub-domains I have setup?

Meaning, I have my domain, mydomain.com, which shows these services -- DNS Domain Name, Domain Registration, Web, Mail. Say I also have this.mydomain.com and that.mydomain.com setup, and the Web Admin Panel shows that Web and Mail are active on each.

If I only want to receive mail at the main domain (user@mydomain.com), and never at the subdomains (user@this.mydomain.com), does it matter if Mail is active or not? Does Mail service have to be active if I have, for example, a PHP script on that subdomain that sends an email?

It's probably a good idea to do this if you're not receiving mail at the subdomain.

No, the mail service doesn't have to be active if you have a script on the subdomain that sends mail.

Cool, thanks! I figure anything I can do to help prevent funkiness like this is worth the effort. Slowly but surely, I'm learning to take advantage of the features DH is offering me, and you, wil (perhaps we should start referring to you guys as /wil+/?) and Jeff are always a big help!