There are at least 2 alternative ways to accomplish this:
Shared mail folder
login as admin
create a mail folder
share the mail folder with the users that should have access to the incoming messages (see sharing mail folders)
in Administration/Mail aliases , create an alias like this: alias=sales target=admin . This will ensure that any mail sent to sales@domain.com is delivered to admin
in Mail/Filters, create a filter like: 'If From contains @ then move the message to mail folder ...' and pick the shared mail folder
whenever an email sent to sales@domain.com is received, it will be stored in the shared folder. In the folder properties you can choose if you want the 'read' flag to be in common, or if every user should have its own read flag
Mailing list
login as admin
in Administration/Mailing lists, create a mailing list 'sales' . Configure it so that the permission to send to this list is 'Public'
add the addresses of the user that should have the incoming messages to the list (NB to the list, not to the users that have permission to send to the list!)
whenever an email sent to sales@domain.com is received, a copy will be delivered to every user in the list. Every user will have its own copy