You can use the SAP domain for RMM. This is standard behaviour.
You can also setup another Private Domain for RMM, if you would prefer sending from and to have customers reply to e.g. email@example.com
SAP domain is email.mycompany.com
- This makes bounce domain bounce.email.mycompany.com
- Click domain will be click.email.mycompany.com, etc.
Private domain is mycompany.com
- This Private Domain DNS is custom and hosted by yourself/client.
- Salesforce SPF should be added to your existing SPF record: existing SPF + “include:cust-spf.exacttarget.com”
- Don’t implement Salesforce MX record for the private domain or it will break the corporate mail! Clients usually disable RMM, so that replies go directly back to corporate employees (e.g. firstname.lastname@example.org)
If you want to keep RMM on anew Private Domain, you must either use a subdomain or a domain not currently used for receiving emails.