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Podcast: Migrating Exchange Permissions When Merging Office 365 Tenants

Jun 25, 2020 by Chris Cahill

Cell phone with a cloud, depicting the podcast on merging Office 365 tenants.

Quadrotech’s Director of Enterprise Migrations, Mike Weaver, recently appeared on the Practical 365 podcast, alongside host and Microsoft MVP, Sigi Jagott.

Mike was invited onto the show to discuss the myriad issues surrounding Exchange mailbox permissions when merging Office 365 tenants – a process that is inherently complex, especially when the source and target have different policies and configurations.

Making allowances for Exchange permissions is critical to the success of your Office 365 tenant to tenant migration, but it can be a step that is often overlooked in the planning stage. Hear what Mike has to say, and learn more in the summary below.

Juggling Permissions When Merging Office 365 Tenants

As noted by Sigi, Mike’s alter ego, ‘MAD Mike’, has steadily gained a faithful following due to his expertise in all things Office 365 for Mergers, Acquisitions, and Divestitures.

Tenant migrations are often the result of large-scale corporate restructuring, and the MAD space is one Mike knows well, having worked on some of the largest Office 365 consolidations in the world – recently helping one client merge 120 individual tenants into a single service.

As such, he knows the red flags to look out for, and mailbox permissions are chief among the issues that cause disruption.

Many assume these permissions refer solely to either delegates (those who have access to an individual’s mailbox for certain operations) or full mailbox permissions, and while these are the most common topics, folder-level permissions must also be accounted for.

What makes this tricky, however, is that some are set by users and others by administrators, so tracking everything down and delivering a consistent user experience becomes a mighty migration challenge.

Additionally, when you factor in the detail that Exchange was the ‘original’ collaboration tool and many organizations have been using it for 10-20 years, you can imagine the complex folder structures and business processes that will have developed over time, and these also need to be navigated.

The Big Stink

If you neglect to migrate Exchange permissions, prepare for the stench of unhappy users and overheated helpdesk lines on the Monday following migration weekend.

Not only will this impact internal operations, but customer-facing processes may also be affected if a workflow is broken somewhere along the line, and this loss of productivity can take time to remedy, especially as these permissions may have been established years ago without any clear documentation.

As Mike advises, before you start merging Office 365 tenants, it’s important to study and make plans for shared mailboxes, user mailboxes, and other accounts. You may choose to move folder permissions for shared accounts but not for end-users, or the other way around depending on the situation.

In mergers and acquisitions, you’re typically moving from a less-mature organization to a more mature environment, meaning you’re less likely to have previously had permission audits on the source. As such, you may find it’s not necessary to migrate absolutely everything, as certain permissions will have become outdated. However, it’s crucial to audit your permissions either pre or post-migration.

Another consideration on this note is the use of Automap for routing mailboxes. If permissions are not up-to-date, users who have transferred through several different departments and didn’t have Automap in the source but do in the target will suddenly have access to several mailboxes, which is a potential data breach as well as causing a bad user experience.

Ultimately, the process of merging Office 365 tenants will be a combination of automating what makes sense and providing documentation for what doesn’t. While it’s possible to migrate everything, it may not be the right thing to do for your organization, so you have to undertake some analysis and careful planning before making the switch.

White Paper and Webinar

As this is such a common pain point for tenant migrations, Mike has recently produced some fantastic content outlining best practice advice.

Firstly, we have a white paper covering everything from full mailbox permissions and shared mailboxes, to calendar permissions, folder permissions, and Outlook delegates.

Download your copy here: How to Manage Exchange Mailbox Permissions in Office 365 tenant migrations

White paper covering mailbox permissions when merging Office 365 tenants.

As mentioned in the podcast, Mike also hosted a fast and furious 20-minute webinar on this topic, and you can access the on-demand recording here.

If you have an upcoming project and would like to discuss our fine-tuned approach to merging Office 365 tenants in record times, please contact our specialist team to learn more today.