Update 9/5/2017–This solution is not supported and does not provide migration of existing attachments. See Tip 971 for additional recommendations on moving CRM attachments to Azure.
Apparently our friends at Microsoft Research have heard Neil Benson’s eloquent explanation of storage costs in Tip #553, as they have released a solution called Attachment Management in AppSource. This solution moves note and email attachments to Azure blob storage, where storage costs are cheaper than Dynamics 365 storage.
The solution includes a plugin called AzureAttachments which handles creation of the attachment in Azure when a note or email attachment is added to Dynamics 365, deletion of the file in Dynamics after the file has been created in Azure blob storage, deletion of the attachment from Azure blob storage if the corresponding note or activity are deleted from Dynamics 365, and retrieval of the attachments when the attachment is requested in Dynamics 365.
Deploying the solution requires an Azure storage account and registration of plugin steps, so be sure that you have the necessary licenses and access to the plugin registration tool.
So now that this solution is available, is there still a place for third party attachment extractor tools? The answer is yes–if you want to store attachments someplace else than Azure Blob storage (such as SharePoint), or if you have many existing attachments that you wish to move to a different location (not just new attachments going forward). Also, keep in mind that this is the first release of this solution, so there may be some rough edges.
But it is great to have a standard Microsoft option that leverages Azure Blob storage, and the solution has some nice functionality, such as an optional web resource to allow users to upload multiple attachments simultaneously.
For more information, see the Attachment Management user guide.