On Fri, 21 Feb 2020 06:00:14 -0600 Tom Browder <tom.brow...@gmail.com> wrote:
> On Fri, Feb 21, 2020 at 05:39 john doe <johndoe65...@mail.com> wrote: > ... > > > I might be missing something here but the domain name is what you > > buy/what you get. > > > Note I own (techically it's more of a rental or lease) multiple > domains hosted across multiple servers which I also fully control (no > sharing, full root control). > > As I understand it, a mail server has to use smtp to physically > transfer mail between physical hosts and that requires one name that > will resolve to an IP. Even if the server is hosting multiple > domains, the mail for each still has to use the one "mailname" for > transport. Not really, you can have an A record for each domain, with the MX record for each domain pointing to its 'own' A record. The only common feature must be the IP address that the A records point to. You may well have only one PTR record for the address, although multiple PTRs on one address are valid, but not many ISPs make provision for that. > > Hence my original question. > I don't really see any reason either way, you can call it fred.example.com if you wish, as long as the MX records point to it. You may well have multiple A records for the address, anyway. An important feature of a mail server is a complementary A-PTR pair, and not all ISPs allow user setting of the PTR. So you may well have an A-PTR pair on the IP address, both supplied by the ISP, which bear no relation to any of your domain names. No problem. If you have external account users, they will need to set up addresses for both SMTP and IMAP/POP, and it is slightly more convenient to use the one name for both, and 'mail' will then be more suitable. It's only when you get fancy, with separate incoming and outgoing servers, that you need distinct and meaningful names. -- Joe