Forum Discussion

Mwkirk's avatar
Mwkirk
Copper Contributor
Jul 28, 2020

Synchronize AD to an existing Office 365 Tenant

So we have a company that we took over IT support for.  They have an AD environment and Office 365 but there is no synchronization.  We have been managing them seperately and they have recently hired...
admin
Mwkirk's avatar
Mwkirk
Copper Contributor
Jul 31, 2020

harveer singh 

 

Ok that is definitely helpful.  I started looking at their ProxyAdresses in their O365.  They apparently had on premise Exchange before because there is a parameter defined for MSEXCHMAILBOXGUID.  Looks like at some point they had Lotus Notes as well becuase I see ProxyAddress values that start with with CCMAIL.

 

What I am thinking of doing is just blanking out all the ProxyAddress values on the local AD then take the export from O365 and import it in so that the ProxyAddress values match up in the local AD and O365.

 

Also, regarding the msexchmailboxguid value which I am thinking I either need to clear that value in the local AD or filter it from the synch.  I have used tools like Skykick in the past for migrations and if you let that value synch then normally it would not let you create a mailbox.  I have no idea what it would do if the user already has a mailbox in O365.

 

Thanks

MK

 

 

harveer singh's avatar
harveer singh
Iron Contributor
Aug 02, 2020
Yup, you are right if you sync the mailbox GUID from on-premises, office 365 will treat you as mail user and won't provision your mailbox. You can either clear all exchange related attributes or simply exclude mailbox guid/Archive guid from synchronization.

Even if you already have a mailbox in office 365, you would still be able to soft match/hard match the users preserving the mailbox, just don't sync the mailbox guid though. And as always, Test with a few users !

Resources