After being asked whether licenses are needed to include shared mailboxes in Microsoft 365 retention policies, I investigated and found that licenses are not. This led to a consideration of the steps needed to create a special retention policy for shared mailboxes (with PowerShell, naturally) and how to avoid retention setting collisions with other policies. All explained in detail here.
Retention policies and retention labels have been around for about 8 years. Some of the older retention settings might use file created dates to remove items. No doubt basing retention on creation dates made perfect sense at the time, but experience shows that maybe basing retention on the last modified date can be better. All explored here together with a script to update retention labels in OneDrive.
SharePoint Online intelligent versioning uses algorithms to decide what file versions must be kept for file recoverability. Unwanted versions are discarded (trimmed). A notional 500 version limit applies when intelligent versioning is in force but if data lifecycle management (retention) is used, SharePoint cannot trim versions to keep within the 500 version threshold. Some change is needed to resolve the conflict.
Intelligent versioning recently appeared in SharePoint Online. The purpose is to save storage by removing unnecessary versions. But retention policies and labels can stop the removal of versions. This article explains what happens when SharePoint Online attempts to trim (remove) unwanted versions of files under the control of retention policies and labels.
In a November 8 post, Microsoft says that Purview Data Lifecycle Management will allow tenants to split processing of Copilot interactions and Teams chats with different policies. The public preview for the change should be available in mid-November. This update makes perfect sense because there’s no logic to dictate that Microsoft 365 tenants want to impose the same retention period for Teams chats and Copilot interactions.