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Why Office 365 Groups are a great destination for Public folder data

Aug 9, 2016 by Romulo Melillo

Migrating to Office 365? Groups are the way to go for better collaboration

For around 20 years, public folders in Microsoft Exchange provided shared access and an easy, effective way to collect, organize, and share information with others in your workgroup or organization.Introduced in the first version of Exchange, public folders were stored in dedicated databases, and could be replicated between servers running Exchange. Their big advantage was that, by being browsable, content could be organized in a detailed, deep hierarchy.

Although they aren’t designed for archiving data, some users who have mailbox limits utilize public folders to archive large items instead of their personal folders (PST files). This affects storage on public folder servers and undermines the goal of mailbox limits. Another drawback is that public folders don’t provide versioning or other document management features, such as controlled check-in and check-out functionality, and automatic notifications of content changes.

By the time Exchange Server 2010 was released, public folders had already become an optional feature, and Microsoft was encouraging its enterprise users to migrate public folder data to SharePoint. But SharePoint lacked much of the functionality users had come to expect from Public folders, and migration was far from easy. However, by 2014 Microsoft had decided the time was right to turn off its last on-premises public folders. So what had changed?

Shared access in Office 365

The big shift has undoubtedly been the rapid and widespread adoption of Office 365. More and more organisations have already migrated – or are planning to migrate – from traditional on-premises Exchange to Exchange Online. But when it comes to collaboration there are a number of options.

The easiest solution is theoretically to migrate to Exchange Online public folders. These can be mail-enabled and added as a member of the distribution group. They still provide simple document sharing and don’t require SharePoint to be installed. And users can still use public folders with traditional Outlook clients: Outlook 2007, Outlook 2010, Outlook 2013, and Outlook Web App, but with some limitations.

In practice, Exchange Online has limits. For organizations that have previously relied heavily on public folders that’s unlikely to be enough leeway.

Read more how to get your team on 'Teams'

A pragmatic alternative is to use Office 365 Groups. There are no limits on the number of groups that can exist within an Office 365 tenant, and their feature set goes well beyond what can be achieved with public folders. As Tony Redmond, Microsoft MVP and all-round Exchange Guru, notes, a group is:

“…a combination of a distribution group and a site mailbox (or even a traditional shared mailbox) because when we look under the hood, we find elements of Exchange and SharePoint mixed together to deliver the collaborative potential that Microsoft envisages for Office 365 Groups. Recent comments by Microsoft indicate that groups are preferred to site mailboxes if you need a collaboration platform for a new project, probably because site mailboxes have been less than successful since their debut.”

More about Office 365 Groups

Groups closely match public folder functionality and have enhanced features around document sharing, threaded conversations, shared calendars and OneNote notebooks, with access to task-based planning via the new Office 365 Planner application. You can access everything through a common portal with much improved reliability and stability.

Tony observes:

“The mailbox is linked with a document library that is apparently created within OneDrive for Business but really is a document library in a SharePoint site with some special UI to make it seem like it’s OneDrive. The document library is intended to provide storage for any other type of content shared within the group. The properties of the group mailbox indicate to Exchange that its membership can be used for routing purposes. Mail sent to the group will be delivered to all members. As such, you can think of a group as being like an Exchange distribution group with storage (the mailbox).”

It follows that, if you’re doing an Office 365 migration, you should consider what you are going to do with your old public folders and how – if you can – you get that data into Office 365 Groups. Determining the target structure and hierarchies is one part of the problem; the other is to make sure you don’t end up migrating more data than you really need. If you really do have public folders with content up to 20 years old, there ought to be plenty of data that can safely be eliminated.

That sounds like a big job, so unless you have a lot of time on your hands and an unerring level of concentration it probably calls for some serious analytics and automation.

Are Office 365 Groups best for you?

We think there are substantial advantages from sharing resources using Office 365 Groups, so we’d certainly recommend you look into this option. It may be that online public folders are all you need, or that you have other ways in mind to maintain collaboration.