All red at System Checks for 2nd Domain on external Server

[kochloeffel]

I use MIB hosting a Domain but with Cloudflare Nameservers and want to use it for another Domain as Mailserver only. The 2nd Domains Registrar is Cloudflare where i use the Nameservers too. Websites of the 2nd Domain I host on another Server. For the 1st Domain all is ok, only yellow at the Status Check for not using MIB as Nameserver.

For the 2nd Domain i only changed the IP of the Subdomain using for the MX Record to the MIB Server. It works, Mails can be received and sent but MIB complaints in the System Check to change it to the first Domains Mailserver Entry: box.domain1.com.

So is it better to change the MX of the second Domain to the first Domains MX which is hosted on the MIB Server or should i leave it to mail.domain2.com? Reputation of the Server is an important Point so i am not sure what to do.

Thanks in Advance

Christian

[alento]

Your mailserver is always the hostname of the box. i.e. box.domain1.com in your example.

Every domain that you host with your MiaB will have the MX record of box.domain1.com. Always.

So on the 2nd Domain undo what you did, and change the MX record to box.domain1.com. You also need to enter the SPF, DKIM, DMARC records that show in the admin area under External DNS. There are to be no A records pointing anywhere for a proper set up.

I am just walking out the door so I cannot elaborate, but the way you currently have it set up will cause delivery and reputation issues in the long run. I can explain in more detail later if you wish.