"Illustration of an envelope icon pointing to a database symbol with the text 'Archive Your Email' below, set against a light blue background with clouds and leaves.

How to Archive Old Emails and Shrink Your Inbox in Outlook

Too many emails clogging your cloud storage? Here’s how to archive them locally and lighten the load.

⚙️ Step 1: Turn Off Cached Exchange Mode (Important)

🕒 Time: 2–3 minutes

Some emails won’t show up for export if Cached Mode is on. Disable it first:

  1. In Outlook, go to File > Account Settings > Account Settings

    Window showing account setting with a submenu open with different choices related to account settings

  2. Select your email account and click Change

  3. Uncheck Use Cached Exchange Mode

    Windows showing the cached mode

  4. Click Next > Finish, then restart Outlook

     ⚠️ Cached Mode helps with speed, but we need it off temporarily to make sure all emails are accessible.

     Note: Turning off Cached Mode might slow things down temporarily—you can turn it back on after the export.

📁 Step 2: Create a Local Archive (PST File)

🕒 Time: 2–4 minutes

  1. Go to New Items > More Items > Outlook Data File

    Windows showing the path to create a PST File

  2. Name the file something clear like Archive_March2025.pst

  3. Choose a location on your hard drive (not a network folder)

  4. Click OK

    Tip: Keep PST files under 20GB to avoid performance issues.

Step 3: Move Emails to Your PST Archive

🕒 Time: Varies – allow 10+ minutes depending on volume

  1. In your mailbox, select emails to archive

  2. Drag and drop them into the new PST folders
    → Start with a few hundred emails at a time

  3. Confirm emails were copied over successfully

  4. Once verified, delete them from your inbox

     Tip: Small batches help prevent Outlook from freezing up.

💾 Step 4: Back Up Your Archive

  1. Close Outlook

  2. Locate your .pst file on your drive

  3. Copy it to an external USB drive or secure network location

     🔍 After copying, open the backup to ensure it works. Corrupt PSTs are real—and annoying.

📉 Step 6: Check Mailbox Size

  1. Go to File > Tools > Mailbox Cleanup

  2. Click View Mailbox Size

  3. Celebrate your slimmed-down inbox 🎉

    window showing mailbox size with all subfolders

🗂️ Bonus: Open a PST File Later

Need to check archived emails down the road?

  1. In Outlook, go to File > Open & Export > Open Outlook Data File

  2. Find your .pst file and click Open

  3. It’ll appear in your folder list as “Outlook Data File”

     ❌ To remove it later, right-click the archive in your folder list and choose Close.

showing folders on the inbox side-bar in outlook

📌 When Should You Archive?

  1. You’re running out of space

  2. You haven’t cleaned your inbox in over a year

  3. You’ve got thousands of old emails you might need, but don’t want clogging up cloud storage

🛠️ Troubleshooting & Tips

Can’t see your archive after importing it?
→ Restart Outlook and check the left-hand folder list

PST file won't open? Says it's corrupted?
→ Use Microsoft’s ScanPST tool

Accidentally deleted something important?
→ Check your Deleted Items or the Recoverable Items folder