DNS zone records

I Understand most of the following default zone records, but what is the purpose of the record for m.mydomain.com and admin.mydomain.com? Are these used by virtualmin for something?

-Jeff

mydomain.com. IN A x.x.x.x
www.mydomain.com. IN A x.x.x.x
ftp.mydomain.com. IN A x.x.x.x
m.mydomain.com. IN A x.x.x.x
localhost.mydomain.com. IN A 127.0.0.1
webmail.mydomain.com. IN A x.x.x.x
admin.mydomain.com. IN A x.x.x.x
mail.mydomain.com. IN A x.x.x.x
mydomain.com. IN MX 5 mail.mydomain.com.
mydomain.com. IN TXT "v=spf1 a mx a:mydomain.com ip4:x.x.x.x ?all"

By default, the "admin" address will redirect to the Virtualmin control panel.

So far as I know, the “m” address doesn’t do anything by itself – with the increasing usage of mobile devices, folks on the road are accessing sites from their phones and pda’s.

I believe the "m" address is created as a convenience, so that you could create "mobile" versions of a site if you so chose (using m.domain.com seems to be the de facto standard for websites built for mobile devices).
-Eric

i thought it depended on what mailbox you are using.
Maildir is default and then there is mbox (using the m.domain.com), but I may be mistaken.

Maildir is default and then there is mbox (using the m.domain.com), but I may be mistaken.

Nope.

m. is the convention for mobile devices to choose a "mobile" version of a site. Beyond the scenario Eric described, Webmin and Usermin are "m." aware, and will serve a mobile theme if one is configured (like virtual-server-mobile).

Has no relation to Maildir or mbox mail spools. And we’d discourage anyone from using mbox mail spools under pretty much any circumstances (they aren’t particularly bad, there’s just no good reason to use them, since Maildir is slightly better in a number of areas).

For real world examples, hit m.google.com or m.yahoo.com.

Thanks for the info and help.

-Jeff