After an Outlook Mobile app update, some folders may stop syncing new email or display outdated content. This happens because the app update can reset or corrupt the local sync cache on your iPhone or Android device. This article provides the exact steps to force a complete re-sync of all folders in Outlook Mobile without deleting your account or losing any data.
The core problem is that the iOS or Android operating system does not automatically clear the app’s local database when an update is installed. The Outlook Mobile app relies on this local cache to show folder contents quickly. When the cache becomes stale or mismatched with the server after an update, folders appear frozen or missing recent messages.
You will learn three distinct methods to trigger a full re-sync: using the in-app pull-to-refresh gesture, the account reset option in settings, and a manual cache clear on both platforms. Each method forces Outlook Mobile to download the complete folder structure and all message headers from Exchange Online or IMAP servers again.
Key Takeaways: Force Outlook Mobile Folder Re-Sync
- Pull-to-refresh on the folder list: Triggers a manual re-sync of the currently visible folder and updates the folder hierarchy from the server.
- Settings > Accounts > Reset Account: Clears the local cache and forces a full re-download of all folders and messages for that account.
- iOS/Android system app cache clear: Deletes the app’s temporary database files without removing login credentials or account configuration.
Why Outlook Mobile Folders Stop Syncing After an Update
Outlook Mobile stores a local copy of your mailbox data on the device to provide fast access and offline support. This local cache includes folder names, message headers, and attachment metadata. When the app updates, the new version may change how it reads or writes this cache. The old cache can contain data structures or indexes that the new app version cannot parse correctly, leading to sync failures.
The sync engine in Outlook Mobile uses a delta sync protocol. It only downloads changes since the last successful sync timestamp. If the update resets this timestamp to an older value or corrupts the timestamp file, the app will not request new messages from the server. The folder list appears unchanged because the app does not recognize that new content exists on the server.
Another common cause is a push notification registration conflict. After an update, the app may lose its push channel registration with Apple Push Notification Service or Firebase Cloud Messaging. Without push notifications, the app falls back to periodic polling, which can be delayed or fail if the polling interval was reset to a longer duration during the update.
Methods to Force Outlook Mobile to Re-Sync All Folders
Method 1: Pull-to-Refresh on the Folder List
- Open Outlook Mobile
Launch the app on your iPhone or Android device. Wait for the main inbox screen to load completely. - Navigate to the folder list
Tap the hamburger menu icon in the top-left corner or swipe right from the left edge of the screen. This opens the full folder pane showing all mail folders, including Inbox, Sent Items, Drafts, and any custom folders. - Pull down on the folder list
Place your finger on the folder list area and drag downward until the spinning refresh indicator appears. Release your finger. The app will contact the server and request an updated folder hierarchy and new message counts for each folder. - Repeat for each folder
Open each folder individually and perform a pull-to-refresh gesture. This forces the app to sync the contents of that specific folder. Do this for Inbox, Sent Items, Drafts, Deleted Items, Junk Email, and any custom folders you use.
Method 2: Reset Account in Outlook Mobile Settings
- Open Outlook Mobile settings
Tap your profile picture or initials in the top-left corner of the inbox screen. Then tap the gear icon in the bottom-left corner of the profile pane to open Settings. - Tap Accounts
In the Settings menu, tap the Accounts option. You will see a list of all email accounts configured in Outlook Mobile. - Select the affected account
Tap the email account that is not syncing folders correctly. This opens the account settings screen. - Tap Reset Account
Scroll down to the bottom of the account settings screen. Tap the Reset Account button. A confirmation dialog will appear explaining that this will clear cached data and re-sync your account. - Confirm the reset
Tap Reset or OK in the confirmation dialog. Outlook Mobile will delete the local cache for that account and begin a full re-sync from the server. This process can take several minutes depending on the size of your mailbox and your internet connection speed.
Method 3: Clear App Cache from Device Settings
If the Reset Account option is not available or does not resolve the issue, you can clear the app cache directly through the device operating system. This method removes all temporary files without deleting your account login credentials.
On iPhone (iOS)
- Open the Settings app
Tap the Settings icon on your iPhone home screen. - Tap General
Scroll down and tap General in the Settings list. - Tap iPhone Storage
In the General menu, tap iPhone Storage. Wait for the list of apps to load. - Find and tap Outlook
Scroll through the app list or use the search bar at the top to find Outlook. Tap Outlook to open its storage details. - Tap Offload App
Tap the Offload App button. This removes the app executable but keeps its documents and data. Then tap Reinstall App to download the latest version from the App Store. Your account credentials remain saved, and Outlook will re-sync all folders after you sign in again.
On Android
- Open the Settings app
Tap the Settings icon on your Android device home screen or app drawer. - Tap Apps or Applications
The exact name varies by manufacturer. Tap Apps to see the list of installed applications. - Find and tap Outlook
Scroll through the list or use the search icon to find Outlook. Tap Outlook to open its app info screen. - Tap Storage & cache
In the app info screen, tap Storage & cache. You will see options for Clear Storage and Clear Cache. - Tap Clear Cache
Tap Clear Cache to delete temporary files. Do not tap Clear Storage because that will remove your account login information. After clearing the cache, force close Outlook and reopen it. The app will rebuild its cache from the server during the first sync.
If Outlook Mobile Still Has Sync Problems After Forcing Re-Sync
Outlook Mobile Shows No Folders at All After Reset
If the folder list appears empty after using the Reset Account option, the app may have lost the connection to your email server. Open Settings > Accounts > tap the affected account > tap Delete Account. Then add the account again using your email address and password or modern authentication. This forces a completely fresh folder sync from the server.
Folders Re-Sync but New Emails Do Not Appear
When folders sync but new messages are still missing, the push notification channel may be broken. On iPhone, go to Settings > Notifications > Outlook and verify that Allow Notifications is turned on. On Android, go to Settings > Apps > Outlook > Notifications and enable all notification categories. After changing notification settings, perform a pull-to-refresh on the inbox to trigger a manual sync.
Outlook Mobile App Crashes During Re-Sync
A crash during the re-sync process usually indicates a corrupt local database that the app cannot read. On iPhone, use the Offload App method described above. On Android, go to Settings > Apps > Outlook > Storage & cache > tap Clear Storage. This is the nuclear option that removes all local data including account credentials. You will need to sign in again after this step.
| Item | Pull-to-Refresh | Reset Account | Clear App Cache |
|---|---|---|---|
| Time required | 10-30 seconds per folder | 5-15 minutes for full mailbox | 2-5 minutes plus re-login |
| Data loss risk | None | None | None if you use Clear Cache only on Android |
| Credentials preserved | Yes | Yes | Yes on iOS via Offload; No on Android via Clear Storage |
| Best for | Single folder not updating | All folders frozen after update | App crashes or reset account fails |
You can now force Outlook Mobile to re-sync all folders after an app update using pull-to-refresh, the Reset Account option, or a device-level cache clear. Start with the pull-to-refresh method because it is the fastest and least disruptive. If folders remain frozen, use the Reset Account option in Outlook settings. For persistent crashes or corruption, the Offload App method on iOS or Clear Cache on Android will resolve the issue without deleting your account. As an advanced tip, schedule a monthly calendar reminder to check for Outlook Mobile app updates and perform a pull-to-refresh on all folders immediately after installing each update to prevent sync delays.