Delegate permissions in Exchange Hybrid – Part One – Introduction

This is the first in a series of posts. You can find links to the other parts of the series here:

Part One – Introduction

Part Two – Full Mailbox Access

One of the most important factors in a successful migration to Exchange Online is correctly batching your users to ensure as little disruption as possible, as even with full Exchange Hybrid in place, you are not guaranteed perfect user experience across premises. And key to batching your users correctly is understanding how delegate permissions work across premises in a Hybrid deployment.

In this series, I will summarise the scenarios that are supported by Microsoft, and those that aren’t, as well as the real world performance of unsupported scenarios, to help you when planning your batches to Exchange Online.

So, as a starting point – what is supported and what isn’t?

  • Full Mailbox Access – Now fully supported cross-premises, whether the delegate or the mailbox are on-premises or in Exchange Online, Full Mailbox access works and is supported. One limitation of this is auto-mapping, which will only work in certain scenarios. More on this later.
  • Send-As Permissions – This is not supported by Microsoft due to there being no central tool to manage this in a Hybrid state, however, manually setting the permissions on both on-premises and Exchange Online will ensure you can have cross-premises Send As permissions, and this is confirmed by Microsoft.
  • Send-On-Behalf Permissions – This is not supported by Microsoft as per the above. However, I have seen different behaviour and will outline this later in the series.
  • Delegate Access/Folder Permissions – These are not supported by Microsoft across premises, and at the time of writing I am not aware of a workaround for this limitation.

These are the expected and stated supportability statements by Microsoft. In Part Two I will move on to testing and demonstrating the expected behaviour of the above scenarios.

If you have any questions or comments please either use the comments section below, Tweet me @MikeParker365 or via email

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