As Exchange Online continues its multi-year directory modernization, we are evaluating the future of several long-standing identifier properties: ObjectGuid (most would recognize this property as Gui...
Updated Sep 02, 2026
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Tell us how you use ObjectGuid, SamAccountName, and DistinguishedName in Exchange Online
Can you clarify which actual property you are referring to as ObjectGuid?
I don't think any of the current cmdlets for Exchange Online (still) expose a property with that name.
I suppose you're referring to the name of the attribute in the directory schema. Am I correct in assuming Exchange Online exposes this as the Guid attribute when calling Get-Mailbox/Get-Recipient/Get-User/.... cmdlets (just like onprem Exchange)?
And what about ExternalDirectoryObjectId (my personal favorite, since that one allows matching objects with their counterparts in Graph/Entra)?
floatkMicrosoft
Hi niehweune1! Good catch, you're absolutely right. ObjectGuid is the directory schema attribute name, and it isn't what you see in cmdlet output. Exchange Online cmdlets surface it simply as
Guid : 1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6dSo your assumption about Get-Mailbox, Get-Recipient, and Get-User is correct.
On ExternalDirectoryObjectId: that one is a different case. It's sourced from Entra rather than being a legacy directory identifier that Exchange Online owns, so it isn't in the same category as the three properties we're reviewing here. It stays a good option for the Graph and Entra correlation you describe and deserves to be your personal favorite 😄.
We've updated the survey to say Guid, and we're getting this post updated as well. Thanks again for flagging this!
This makes it a bit odd now. By ObjectId had assumed its external obj id from Entra. And we got a lot of guids exchange guild, archive guid etc. Guid specifically in EXO would be rarely used, so far haven't seen anyone including myself using that.
- floatk
Hi Satyajit321! You're completely right that there are several GUID-shaped identifiers on an EXO object, and that's precisely why we're looking at whether a smaller set would simplify the admin experience. Your observation that the EXO-originated Guid doesn't seem to be used much is exactly the kind of input we're after, and I'd encourage you to share it in the survey as well. Thanks!
