Azure ADSync Creating Addresses which do not exist in AD

Hi,

We've got an odd issue when we're syncing our ActiveDirectory with Office365.

There seem to be odd accounts that do not existanywherein AD being created in Office365 with usernames like: "alias_3f81200@domain.onmicrosoft.com"

These are causing sync errors with shared mailboxes related to the proxyaddress attribute - That is:

"Unable to update this object because the following attributes associated with this object have values that may already be associated with another object in your local directory services: [ProxyAddresses smtp:user@domain.com;]. Correct or remove the duplicate values in your local directory. Please refer tohttp://support.microsoft.com/kb/2647098for more information on identifying objects with duplicate attribute values."

Following the instructions provided by the link do not resolve, or find these odd accounts. IDFix...