Re: Use Own DNS servers.

Hi KMR NYC,
 
As I understand it, you add the custom domain to Office 365 Portal, but you don't want to Office 365 hosts the custom domain.
 
If so, to use Office 365 service (Lync Online, Exchange Online, SharePoint Online), you need to create  related DNS records at the domain hosting provider. For detailed information about it, please refer to the following articles:
Create DNS records at any DNS hosting provider when Office 365 doesn't host your DNS
http://onlinehelp.microsoft.com/en-us/office365-smallbusinesses/jj655392.aspx
Add your domain to Office 365 but continue to manage your domain's DNS records
http://onlinehelp.microsoft.com/en-us/office365-smallbusinesses/hh416759.aspx
 
Thanks,
Ida Qiu