I have a customer who is just about to go live, we set the tenant up with all users having a login/ email domain name address of the new brand for the company, lets call it  <firstname>.<lastname>@ABClimited.co.uk, but when they go-live they want to use their old company name domain for the first 2 months until they do a rebrand launch, for example <firstname>.<lastname>@XYZco.uk.

Has anyone got any ideas how we can do this, so we can set up an alias with the old domain name so that we catch the incoming email, but the outgoing email sent from within CRM/ Dataverse will use the login email, which will be the new domain we do not want in the first 2 months.

Any ideas will be greatly appreciated.