Email archiving is one of those IT topics that nobody thinks about until they need it — and by then, it’s too late. A client subpoenas three years of email. A staff member accidentally deletes a critical thread. A regulatory audit asks for correspondence from 2023. If you don’t have archiving configured, you’re in trouble.
The good news: Microsoft 365 includes email archiving at no additional cost on most business plans. The bad news: it’s not on by default. Here’s how to set it up, step by step.
Why email archiving matters for Miami businesses
Beyond simple storage management, email archiving serves two critical purposes. First, compliance: Florida Bar rules require attorneys to retain client communications for six years. HIPAA requires covered entities to retain records for six years from creation or last use. Many other regulated industries have similar requirements. Second, litigation readiness: if your business is ever involved in a dispute, you may need to produce email records quickly and completely. Without archiving, that may be impossible.
Step 1: Enable the archive mailbox for each user
In the Microsoft Purview compliance portal (compliance.microsoft.com), navigate to Data lifecycle management > Microsoft 365 > Archive. You’ll see a list of all users in your organization. Select the users you want to enable archiving for and click “Enable archive.” Microsoft will provision a separate archive mailbox — this may take a few minutes.
Note that archiving requires at least an Exchange Online Plan 2 license, or a Microsoft 365 Business Premium, E3, or E5 subscription. Standard Microsoft 365 Business Basic and Business Standard plans include archiving, but check your license before proceeding.
Step 2: Create a retention policy in Microsoft Purview
Enabling the archive mailbox just creates the storage space. You need a retention policy to control what gets moved there and when. In Microsoft Purview, go to Data lifecycle management > Retention policies > New retention policy.
Give the policy a name, choose “Email” as the location, and set it to apply to all mailboxes (or specific ones). Set the retention period to match your compliance requirement — six years for law firms and medical offices is a safe starting point. Choose whether to retain-only (items stay in place until the period expires) or retain-and-delete (items are deleted after the retention period). For most businesses, retain-only is appropriate unless you have a documented records destruction policy.
Step 3: Set the archive timing with an MRM policy
Messaging Records Management (MRM) policies control when items are automatically moved from a user’s primary mailbox to their archive mailbox. By default, Microsoft includes a “Default MRM Policy” that moves items older than two years to the archive. You can modify this or create a custom policy.
To create a custom MRM policy, go to the Exchange admin center > Compliance management > Retention tags. Create a “Move to Archive” tag with your desired age (e.g., 1 year), then create a retention policy that uses that tag, and assign the policy to your users’ mailboxes.
Step 4: Trigger organization-wide mailbox processing via PowerShell
After applying a new MRM policy, Microsoft processes mailboxes on a schedule that can take up to seven days. To force immediate processing across your organization, connect to Exchange Online via PowerShell and run:
Get-Mailbox -ResultSize Unlimited | Start-ManagedFolderAssistantThis triggers the Managed Folder Assistant to process every mailbox immediately. For large organizations with thousands of mailboxes this can take time, but for most small Miami businesses it completes within an hour.
Step 5: Verify it’s working
After processing, ask a test user to check their Outlook. They should see an “Online Archive” folder in their folder list alongside their regular mailbox. Items older than your configured threshold should begin appearing there. You can also verify via the Exchange admin center that archive mailboxes are provisioned and showing storage usage.
Common mistakes to avoid
- Not testing a restore: Archiving is only useful if you can retrieve items when needed. Test the process of searching and exporting items from the archive before you need to do it under pressure.
- Forgetting shared mailboxes: Generic mailboxes like info@ or support@ often contain business-critical email. Enable archiving on shared mailboxes too.
- Confusing archiving with backup: Archiving retains email per your policy, but it’s not a backup. If someone deletes an item before the retention policy has processed it, it may not be in the archive. A separate email backup solution provides an additional safety net.
- Applying too short a retention period: When in doubt, retain longer. Storage in Microsoft 365 is cheap. Recovering from a situation where you needed records you didn’t retain is not.
Don’t want to do this yourself? We handle Microsoft 365 archiving setup and ongoing administration for Miami businesses — including law firms and medical offices with specific compliance requirements. Get in touch with SKALS IT and we’ll take care of it.