Clean up your backlog

Sort the mail already in your mailbox, safely and paced.

Backlog cleanup sorts the mail that's already in your mailbox, applying your sorting rules to messages that arrived before you connected. It's a one-time sweep you run from the dashboard.

Before you start

The control shows how many messages are eligible and how many folders are in scope. Cleanup is paced and chunked so Microsoft never throttles your mailbox. Large inboxes are handled steadily over time rather than all at once. You can watch a live progress bar while it runs.

Backlog cleanup is part of a paid plan. A free trial gets a one-time taste: up to 2,000 existing emails in total across all cleanups (the control shows how much is left), and on an expired trial you'll be prompted to subscribe first. Subscribing finishes the rest of a taste-capped sweep automatically. New mail always files live regardless. See Billing & plans.

Protecting folders

Press Protect to open the folder picker and choose folders the sweep should skip entirely. Sensible defaults (like Archive) are pre-selected. Protected folders are never touched. Outlook's system folders are always safe.

This is the main thing to get right: if there's a folder you've already organised by hand, protect it before you run.

Running it

Press Run cleanup now. Messages are filed using your current sorting rules and filing modes, and each one appears in the activity feed and audit log as it's processed. Anything filed by mistake can be reversed with Undo, just like live filing.

If you've deleted a folder Sortfully made, a cleanup recreates it for mail that's still in your Inbox, just as new mail would. Mail you've already put in your other folders isn't moved into a folder you deleted. Kept messages, senders on Keep in Inbox, and mail you've dragged back to your Inbox always stay where they are.

A cleanup of years of mail creates a folder for every sender in it. If Tuck away quiet folders is on, folders whose newest mail is older than your chosen period move into QUIET SENDERS - SORTFULLY once the cleanup finishes. See Settings.

If you'd rather not

Leaving backlog cleanup off (the choice you can make during onboarding) means Sortfully only acts on new mail from now on, and your existing folders are left exactly as they are.