Steps to reproduce.
Click on a subserver under a virtual server.
Click Edit users.
Either Create a new user, or Edit an existing user by clicking on the user name.
You'll see "Edit User", "Virtual domain user mailbox details".
For our example, email address is
IMAP login is
Click on "Email settings", "Additional email addresses".
Hover over the label "Additional email addresses" and mouse pointer turns into the "help poniter".
Click the label "Additional email addresses", it shows the popup box, "This text box can be used to easily add extra email aliases for this user. These aliases will also be visible and editable in the mail aliases list. "
Enter the following in the box, one per line:
Click the "Save" button at the bottom of the page.
On the menu (left side of page), click "Mail Aliases."
See the entries:
administration Address admin.mydomain
administrator Address admin.mydomain
Try sending email to those alias addresses.
You get bounces when you send to the alias
Are the above aliase entries incorrect / broken?
Shouldn't the aliases be set like this?...
administration User admin.mydomain
administrator User admin.mydomain