Office 365 important DNS knowledge

Last week Microsoft launched Office 365. Office365 is clearly a great product. Microsoft offers three different “plans”. One is for small businesses, Plan P, maybe stands for Professional or Personal. Plan P is a offer for small businesses with less than 26 users. For bigger companies or Enterprises Microsoft offers Plan E (Enterprise) which also includes Plan K (kiosk workers).

Now there are a lot of differences between this plans which are described on the Office365 website. But there is something I just realized after I used Office 365 the first time. If you want to use Office 365 with your own domain, Microsoft has two ways to do this.

With Plan P you have to delegate all the DNS configuration to Microsofts DNS servers, which means your DNS servers for your domain, will be somednsserver.microsoft.com. Microsoft offers you a simple UI to create additional CNAME and A records. And all your MX records and A records which are used by Office 365 will be created automatically. This makes it very easy, but even for some small businesses this does not work, because they may need more than just some simple additional A records or CNAMEs.

If you wanna use your own DNS servers or the DNS servers of your provider, you have to use one of the Enterprise plans (there are more than one plan). With a Plan E1 for example, you can choose to delegate all the DNS administration to the Microsoft DNS servers or you can choose your own, maybe already existing public DNS servers. In this case Microsoft tells you which DNS records you need to create (MX, TXT and A records).