Cannot change default email address through Active Directory

[aacservices]

We have several domains on our Scalix server e.g.

• company.com
• company.co.uk
• company2.co.uk

Most users have all of the email domains set up for them as aliases e.g.

• billg@company.com
• billg@company.co.uk
• billg@company2.co.uk

I want to change a users default email address from billg@company.com to billg@company2.co.uk
In Scalix v10 there was a box in the Active Directory Users & Computer (ADUC) GUI extension to set the default email but this seems to have disappeared in version 11?!?

I was under the impression that the top email address in the Scalix General tab of ADUC was meant to be the default but there seems to be no way of changing the order.

Is anyone able to clue me in on how to make the change?

Scalix Server version = 11.4.4.12886
AD GUI Ext version = 11.4.6.851