Priority Cleanup: an important new tool for M365 governance

Microsoft’s launch of Priority Cleanup has gone under the radar for many – but I feel it could be one of the most important improvements for Records Management in Microsoft 365 for several years.  I’m wondering if this tool might be the answer to some of the GDPR compliance headaches that many face when managing records in Microsoft 365.

What is Priority Cleanup?

Available as a preview capability in Microsoft Purview, Priority Cleanup provides a tool for bypassing both eDiscovery Holds and retention labels/policies, enabling the deletion of content that it would not otherwise be possible to delete.

The current preview of Priority Cleanup only functions in Exchange, allowing us to purge emails held in the Substrate Hold folder. That said, Microsoft is planning to partially extend Priority Cleanup to both SharePoint and OneDrive at some point this month (September 2025). Information around precisely how this will work is scarce at the moment, but this might eventually allow us to delete records from the Preservation Hold Library – something I’ve been arguing we need for years now.

To be clear, I've not yet seen Microsoft state that they will be extending Priority Cleanup to fully support the deletion of records from the Preservation Hold Library. The September 2025 update (that I've linked to above) only commits to provide "new support for SharePoint and OneDrive with the main scenarios being the ability to delete Teams meeting recordings and transcripts ... and delete items retained in a user's OneDrive Preservation Hold Library after the user has left the organization". It is, however, certainly a step towards providing us with the full ability to purge any record we need to delete from PHLs - something I'm hoping to see provided in coming months.

Why do we need this tool?

The main reason that I’m paying close attention to the progress of Priority Cleanup, is because it has the potential to resolve what I consider to be one of the biggest issues with retention in Microsoft 365, namely the ability to comply with GDPR’s ‘Right to erasure’.

The problem that organisations have faced is that many of the approaches for retention in Microsoft 365 lead to records being stored in indelible locations, such as the Preservation Hold Libraries (PHL) (in SharePoint) and the Substrate Holds folders (in Exchange). Once records enter these locations, even if you are obliged by GDPR, you are often completely unable to delete them.

As an aside, I think it’s important for me to explain that my view before the introduction of Priority Cleanup was that the Preservation Hold Library was superb for Legal Holds, but not suitable for managing records for anyone needing to comply with GDPR. The rationale here is the typically Legal Holds are a legitimate reason for rejecting a GDPR right to erasure request, while the fact you have applied retention to a record simply isn’t.

I am aware of multiple organisations who have all been struggling with this problem over the past few years. For example, one UK Public Sector body has told me that every few months they are obliged to delete records from the Preservation Hold Libraries, in order to comply with GDPR. Each time they need to do so, they need to undertake the following process: 

• Exclude the site containing items they need to delete from the scope of their retention policy.

• Wait until this change takes effect. Then delete the relevant records from the Preservation Hold Library.

• Quickly reapply the retention policy to the site (to prevent the loss of any records that they wish to keep).

I should point out, that while this painful process is just about viable with retention policies, I’m not aware of any similar procedure for retention labels. In other words, if you allow retention labels to store records in the Preservation Hold Library (which is their default configuration) you will currently be struggling to comply with GDPR. This is why I have spent the past few years advocating that the best way to use retention labels is to disable Purview’s global records management setting that causes records to be stored in the Preservation Hold Library (see: https://www.robbath.co.uk/post/m365-records-management-settings-page).

In this context, you can probably see why I feel that if extended, Priority Cleanup will be a huge step forward. We might finally have a tool that allows us to honour GDPR obligations, while still using the Preservation Hold Library for managing records. Once Priority Cleanup is updated to allow deletion of any files from the PHL, (and assuming it continues to be supported by Microsoft), I will be changing my guidance by suggesting that organisations enable their ‘Deleting content labelled for retention’ settings.

How does Priority Cleanup work?

It’s a little bit complicated to understand how you can make use of Priority Cleanup. At a high-level the following steps need to be undertaken:

• Admins create a ‘Priority Cleanup policy’ in Purview

• Each policy is targeted at specific locations and is configured with a KQL query to identify precisely which items are included in the scope (in the same way auto-labelling policies work)

• All items found by the policy will then need to be reviewed. This functions in a similar way to the Disposition Review process, with reviewers deciding whether to delete or re-label each item.

• A second review is required before content, previously protected by a retention policy, retention label or legal hold, can be deleted.

• At the end of the review process, all items that have been selected for deletion will be automatically purged from the tenant.

For anyone after more information around precisely how Priority Cleanup currently works, I recommend you to take a look at a couple of excellent blog posts from Tony Redmond and Vasil Michev.

One unsurprising disappointment is that the Priority Cleanup requires an E5 (or equivalent) licence to use:

Final Thoughts

Priority Cleanup looks like it could fundamentally change the guidance I will be providing around how retention labels are configured in Microsoft 365. That is, of course, assuming that the tool is extended to successfully allow organisations to delete content from Preservation Hold Libraries.

I do feel that Priority Cleanup seems a little overly complicated to use.  I was hoping that we might get a simple delete button for administrators to simply choose to override retention and delete content that they are obliged to remove. Instead, it feels like they have to jump through hoops in order to find, review, and approve records before they are deleted.

Overall, I’m delighted by the potential offered by Priority Cleanup and feel that it’s not currently getting the attention that it deserves.