It may be a little unusual, but i think it maybe useful to be able to change the default dns entries that are created for each website. even on a per reseller basis. i tried enabling the default mx option but my new sites aren't actually creating a mail A record in dns at the moment. In the manual it says mail A records should be created and default MX pointed at them, but my system points the default MX at www host, which works fine, but still confused some of my users who expected to point their outlook clients at mail.domain.tld, or pop3.domain.tld and these weren't responsive to their dismay. Simple little house keeping issues for interaction between us knowledgable admins and the neophytes we serve.