Cannot createOutlook profile with MyDomain.com only Comcastbiz,net domain

Can not create user 2010 Outlook profile with Comcast hosted private domain. We have other PC's that have succesfully configured outlook profiles using private hosted domain.  Same machine can configure an outlook profile using Comcastbiz.net domain, but not the hosted domain. Read there is a fix, but need engineering to fix.  I can't wait several days.  I have several CR # tickets and no response from 2nd tier customer support.  This is not PC/machine specific problem.  We have tried to configure same user profile on another machine. Same error, "Cannot connect with exchange server."