Migration and Public Folders – Stuck On Premise

When it comes to Exchange Public Folders, it’s all too common to find that companies are still hosting them on premise while mailboxes are in Office 365. Some have been in this configuration for months, if not years!

Companies are in this situation because they believe there is either no migration path or they have tried and failed.

Keeping on-premises Public Folders is significant risk to the company. For one, you are still hosting important message content on premise. It also requires that your staff still maintain an Exchange server footprint, requiring server maintenance and backups. Companies miss out on the backup and management benefits of hosting Public Folders in Office 365.

Why are Public Folders Still On-premises?

Reasons for why Public Folders are still on premise fall into the following areas:

  1. Migrating them using the Microsoft approach requires too much time and resources
  2. Public Folders are so tied to business processes that moving them is too risky
  3. Third party solutions still require time and resources and have a low success rate
  4. Uncertainty around newer Office 365 Public Folder upgrade options, such as Groups

Manual Migration Method

We discussed many of the issues in previous posts in how the manual migration method is difficult, painful, and full of risk. There’s a high level of understanding needed before you can begin, and most people don’t have the time. Even with the high degree of understanding, mitigating risk can prove challenging. You need to know the right scripts to use and when to use them, and what they need in order to run successfully. Finding this information can be difficult. An environment with even a few hundred folders in it can make this a difficult task.

If you make it past the scripts, you then need to understand the Office 365 limits for Public Folders. How you map your environment to fit within these limits can make or break your migration.

To run the migration, you will need to be comfortable with a process involving CSV files and not much information on the progress being made. Locking down your Public Folders for the length of the migration is expected. If you have a small environment, then this might not be a problem. If your company uses them even moderately, you will need to be prepared for this to be days or even weeks.

Public Folders and Business Processes

It’s common to find Public Folder usage tied to a companies business processes. The reasons behind why this occurs are as follows:

  • They are accessed through Outlook, which everyone in the company has access to already for email
  • Deployment is really easy and you can get started in a matter of minutes
  • Common and familiar folder hierarchy
  • Simple sharing to multiple users without sending messages back and forth
  • Easy to apply permissions to folders
  • Mail can be delivered directly to a specific folder
  • Mail can be sent on behalf of a mail-enabled folder, such as for a specific team or department

Once Public Folders become wrapped in business process, change of any kind can be difficult. When combined with complicated and difficult migration processes or alternatives, companies can find themselves in a stand still. In the case of migrations, companies need to have confidence that they can move them, such as to Office 365, with no disruption to end users.

Sometimes, in addition to a migration, new features might be considered, such as SharePoint, Shared Mailboxes, or Office 365 Groups. Functionality is better in some areas, but whether or not they match to a companies needs can be challenging. Combining a change in features plus a migration makes acceptance more difficult and expensive. Not only do you need to do the migration, but you also need to fit it to the business process and provide training. A failure to handle any part of that process and acceptance will fail. A much better option is to migrate your Public Folders first. This keeps your business processes intact while offloading the remaining Exchange on premise resources. You then have time to research options for future Public Folder content.

Third Party Migration Solutions

There are many third party solutions that have been on the market for years that migrate Public Folders. However, they use the Microsoft Migration API and scripts in order to work. This is no different than running a Public Folder migration manually other than having a user interface to work with. This means they will suffer from the same problems as the manual migration method, just look better while they are failing you.

Then there is the trend amongst solutions that are more about synching your Public Folders rather than migrating them. This doesn’t relieve you of hosting your Public Folders on premise, so you never see the benefit of offloading it to Office 365.

It’s best to research the solutions first and compare. Knowing what you should be considering will help you.

Public Folder Upgrade Paths

In addition to a straight Public Folder migration, there are other options available within Office 365 that can replace some of the functionality. Some of these options are:

Some of these options may be a better replacement and some may not be able to replace all of the features of Public Folders. It really depends on how your companies business processes use Public Folders. If you are using all of the Public Folder features, then you will be hard pressed to find an apples to apples comparison. This makes it difficult to consider both a migration of Public Folder content to Office 365 while adopting one of these options listed above. It’s more likely you will want to expand to one of these options in addition to the continual use of Public Folders.


When Public Folders remain on premise, it prevents a company from fully utilizing the value of Office 365. The burden of Exchange backend management is still on the IT team in these cases. This provides risk to the business, especially since many businesses that use Public Folders have their business processes mixed in with it. Migrating your Public Folder content to Office 365 will help you fulfill the promise of Office 365 and liberate you from expensive on premise maintenance. Once there, you can expand your use of additional Office 365 services to compliment your Public Folders.

If you would like to learn more about how ExchangeSavvy can help you solve your Public Folder migration needs, please reach out to us! We have completely de-risked the Public Folder migration, with no impact to your end users.

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