My Outlook email inbox has been a big mess with over 30,000 emails in multiple folders. Sure, you can adopt some habits that can help you achieve inbox zero, but they still don’t fix the existing mess that’s in my inbox and the future messages that I’ll receive.
While looking for ways to automate the cleanup process, I found the AutoArchive option that’s been there all this time that can reduce mailbox size by moving old items to an archive data file. Just what I needed, except it’s an Outlook Classic feature, and not available on the new Outlook for Windows. Personally, I still use the classic Outlook client, so this wasn’t an issue.
What’s AutoArchive?
It automatically moves old emails to a separate data file
When you archive an email in Outlook, the older emails move out of your main inbox to keep things organized without permanently deleting anything. You can do this manually using the Archive button in the ribbon or the Archive option in the right-click context menu, but that still requires you to select and move emails yourself.
AutoArchive automates the entire process. You set the rules once, such as how old an email should be before it’s moved, how often the cleanup should run, and Outlook handles the rest in the background. It checks your folders on a schedule and moves anything that meets your age criteria.
Once emails are archived, they go into a separate Outlook Data File (.pst) stored locally on your computer, typically in your Documents\Outlook Files folder. This is the key detail that makes AutoArchive different from simply hitting the Archive button. The button just moves emails into an Archive folder within the same mailbox, so your mailbox size stays the same. AutoArchive actually moves them out of your mailbox entirely, which is what reduces the overall size. Your archived emails are still accessible in Outlook, but they just live in a different file. You can open the archive .pst file anytime by going to File > Open & Export > Open Outlook Data File and browsing to its location.
Setting up AutoArchive
Turn it on and configure the cleanup rules
To set up AutoArchive, make sure you are using the Classic Outlook client. Then open Outlook, go to File > Options, and select the Advanced tab on the left. You’ll see an AutoArchive section with an AutoArchive Settings button; click it to open the configuration dialog.
Check the box that says Run AutoArchive every X days. The default is 14 days, but you can set it anywhere from 1 to 60 days depending on how aggressive you want the cleanup to be. I keep mine at the default 14 days since that strikes a good balance between keeping things tidy and not running too frequently.
Below that, you’ll find the cleanup rules. The Delete expired items (e-mail folders only) option removes emails past their expiry date. Archive or delete old items is the main toggle that enables the actual archiving. Under Clean out items older than, you pick the age threshold—anything from 1 day to 60 months. I set mine to 6 months since I rarely need emails older than that in my active inbox.
Finally, choose where your archived emails go. The Move old items to option lets you pick or create a .pst file, with the default being Archive.pst in your Documents folder. There’s also a Permanently delete old items option, but I’d avoid that unless you’re sure you won’t need those emails later. Once they’re deleted this way, they bypass the Deleted Items folder entirely. You can also check the Prompt before AutoArchive runs option if you want a heads-up before each run, giving you the chance to cancel if needed. Click OK, and AutoArchive starts running on your chosen schedule.
Configure it for custom folders
By default, it only covers a few folders
Importantly, AutoArchive doesn’t run on all your folders by default. It only covers Sent Items, Deleted Items, Calendar, and Tasks. That means your Inbox, Drafts, and any custom folders you’ve created are left untouched unless you specifically tell AutoArchive to include them.
To add a folder, right-click it in the Navigation pane and select Properties. Go to the AutoArchive tab, and you’ll see three options. Do not archive items in this folder skips it entirely. Archive items in this folder using the default settings applies whatever global rules you configured earlier. The third option, Archive this folder using these settings, lets you override the defaults for that specific folder, which is useful if you want your Inbox archived after 3 months but your project folders after 12 months.
I went through my folders one by one and enabled AutoArchive for my Inbox and a handful of project-specific folders. It took a few minutes, but it’s a one-time setup. For folders like Calendar and Tasks, you can’t right-click to access Properties directly—instead, select the folder and go to Folder > Folder Properties on the ribbon to find the AutoArchive tab.
If you later change the global AutoArchive settings and want them applied everywhere, go back to File > Options > Advanced > AutoArchive Settings and click Apply these settings to all folders now. This resets every folder to use the default settings, so use it carefully if you’ve set up custom rules for individual folders.
A long overdue cleanup
AutoArchive isn’t a flashy feature, and that’s probably why I ignored it for years. It quietly moves old emails to a separate file on a schedule you define. But for someone sitting on 30,000 emails across multiple folders, that’s exactly what I needed.
The only thing to keep in mind is that AutoArchive is exclusive to classic Outlook for Windows. If you’ve already switched to the new Outlook client, you won’t find this option. And if you have multiple Exchange accounts in the same Outlook profile, configuring AutoArchive for one applies the same settings to all of them—something worth knowing if you manage a shared mailbox alongside your personal one. But if you’re still on classic Outlook like me, there’s no reason to leave this feature turned off.
