> Yes, I have been doing this for many many years, what I have not done > previously > is create an MX record for mail.otherdomain.com pointing to the same IP as > main.maindomain.net
Clearly I am no expert, so this is just my 2cents. I think pointing otherdomain.com to MX=mail.example.com is less headache then using MX=mail.otherdomain.com pointing to the same IP. Because now you need to worry about setting up separate SPF, DKIM, DMARC and SSL certificates for mail.otherdomain.com, which is completely doable, just more to do. I prefer the KISS approach, less moving parts to break and all that, and at the end of the day how many email users look at the hostname of the email server that delivered their email? -
