Automapped mailbox - Migration

[CoopBK]

Hi everyone.

We're looking at an AD consolidation project moving users from one internal forest to another with 1 o365 tenant in the cloud.  Multiple forest on prem to 1 O365 tenant.  

We're moving users from forest 1 to 2 and when we move the shared mailboxes and users, we're looking at how to know who has the mailbox automapped and who doesn't.   Never had a good answer from MS on this.  Does anyone know how to tell if a users is automapped or not? 

Tagging @Vasil Vasilev  as I know he's played with this a bit from previous posts.  Thanks in advance all. Brian

[#2]

Hey @CoopBK 

My understanding is the automapping data is stored with the AD user under msExchDelegateListLink

Get-ADUser "Mailbox01" -Properties msExchDelegateListLink | Select msExchDelegateListLink

The above should show you which users get the Mailbox01 automapped in Outlook, but I'm away from my lab and unable to test right now.

Hope this helps

Cheers,

Mark

[#3]

The MSExchDelegateLinkListBL is the "reverse" attribute, which will give you a list of all the mailboxes a given user has automapped. 

[#4]

So all the mailboxes are in office 365 so is there a way to see it then? @VasilMichev 

[#5]

Nope. At least not a supported way. You can use the method I've outlined here, but that requires you to add folder-level permissions: https://www.michev.info/Blog/Post/1926/peeking-behind-the-curtain-of-exods-fetching-the-adrecipient-...

In any case, you can simply report on the Full Mailbox permissions instead and assume they're all with automapping set to $true.