> On 02-25-2022 2:58 pm, post...@ptld.com wrote: >> No, they use "mail.example.com" which normally would not exist, both for >> IMAP and SMTP. >> If the clients do not care that the mail server is not the mailserver, >> perhaps I am overthinking this. > > > One idea would be to leave mail.example.com as an A record pointing to the > submission server > IP. > Then change the naming scheme for the MX server, like... > - server1.mail.example.com > - 23-112.mail.example.com (IPv4) > - C60D.mail.example.com (IPv6) > - smtp.mail.example.com > - smtp.example.com > - mx.example.com > > Im rambling, but you get the point. > Leave mail.* for user clients and use something else for MX records.
Oops, i forgot to conclude after all that... If you changed the MX to smtp.mail.example.com then you can also set the MX record for otherdomain.com to MX=smtp.mail.example.com while user clients still use mail.example.com for submission and the world continues to turn. The MX and mail.example.com could point to the same physical server or separate servers, and you have the flexibility to change either or both in the future without interruption to end users. Aside from DNS propagation issues depending how you roll it out.
