I have seen a similar topic here, but unable to figure out the solution derived from that topic. Since I am new here I hope someone would help me simplify the solution for this issue. Here is it: I had created my box with admin@example.com. Now I need to create a user on a different domain name which is admin@exampletwo.com. But the system says this: “You may not make a user account for that address because it is frequently used for domain control validation. Use an alias instead if necessary”.
That is a situation that should not have happened as Mail-in-a-Box does not allow domain control email users to be created.
I am afraid that your only solution is to follow the guidelines provided with the system message that you receive. Point your domain’s admin user alias at another email user account.
How am I supposed to do this. When creating the first user with another domain, the system creates automatically 3 alias (Admin@…) pointing to the initial created admin account . These cannot be changed or added anything to it.
In my case I created mail mailinabox with a subdomain
and now I am stuck, cause I cannot changed/edit anything of these aliases, create users and cannot send from these alias, cause there is no user in the acceptance list for that alias, only another alias who refers to a user. I would love to change that, but there is simply no way to do so.