Clear Outlook Cache on iOS: Safe Steps That Work

To clear Outlook’s local cache on an iPhone or iPad, open Outlook, tap your profile icon, tap the Settings gear, select the affected account, and choose Reset Account if that option appears. This refreshes locally stored Outlook data and makes the app sync again; iOS does not provide a general-purpose Clear Cache button for Outlook. Before you start, confirm that important messages and drafts have synced, because anything stored only on the device may not come back.

What You’ll Need

An iPhone or iPad with Outlook installed and an internet connection. Wi-Fi is preferable if the mailbox is large or has many attachments to download again.
The email address and sign-in method for the account. Keep access to any password, authenticator app, security key, or work sign-in approval that your organization requires.
A few minutes for Outlook to reconnect and synchronize. The time depends on mailbox size and connection speed.
For the reinstall fallback, your Apple Account and access to the App Store. You may also need to sign in to Outlook again after reinstalling.

Step-by-Step

Check whether the problem is in the app or the mailbox. Open the same email account in its webmail service, such as Outlook on the web, or another trusted mail app. If a message is missing there too, clearing Outlook’s cache will not restore it; the issue may be with the account, server, or message itself. If the mailbox looks correct elsewhere but Outlook is stale, a local refresh is a reasonable next step.
Make sure recent changes are not waiting to upload. In Outlook, check the Outbox and any drafts you have edited. Send queued messages when you have a connection, and copy the text of any important draft that you cannot confirm is saved to the account. If you use a work or school account, check whether your organization has instructions for preserving locally stored information. Do not assume that every unsent item exists on the mail server.
Try a basic refresh first. Connect to a reliable network, open Outlook, and pull down on the message list to request a sync. If the screen is frozen, close Outlook from the iOS app switcher and reopen it. On an iPhone or iPad without a Home button, swipe up from the bottom and pause to show the app switcher; on models with a Home button, double-click it. Closing and reopening may resolve a temporary display or connection problem without resetting the account.
Open Outlook’s account settings. In Outlook, tap your profile picture or initials near the top-left corner. Tap the gear icon to open Settings. Under the mail accounts section, tap the account that is behaving incorrectly. The exact labels or location can vary slightly by Outlook version, so look for the account-specific settings rather than the iPhone’s general Settings app.
Choose Reset Account. Scroll through the selected account’s options and tap Reset Account, if shown. Read any confirmation prompt, then confirm that you want to reset. This tells Outlook to rebuild or refresh its local account data. It is not the same as deleting the email account from the provider, and it should not delete messages stored on the mail server. If you do not see the option, update Outlook from the App Store and check again; if it remains unavailable, use the reinstall method below.
Keep Outlook open while it reconnects. Return to the inbox and allow the app to sync. Depending on the account and connection, it may take a little while for folders, message lists, and attachment previews to repopulate. Newer messages may appear before older mail or large attachments. Avoid repeatedly resetting the account while this process is underway, since doing so can interrupt the refresh.
Verify that the refresh worked. Check the inbox, sent items, and any folder that was previously failing. Open a recent message and confirm that its contents load. If you made a draft or queued a message before resetting, verify whether it is still available before recreating or sending it. A message that is still present in webmail but absent in Outlook points to an app sync issue; one missing from both may need account-level investigation.
Reinstall Outlook only if Reset Account does not help. First verify that you can sign in and that important drafts or unsent items are safe. On the iPhone or iPad, go to Settings > General > iPhone Storage (on an iPad, the menu may say iPad Storage), select Outlook, and tap Delete App. You can also touch and hold the Outlook icon, choose the option to remove the app, and select Delete App, not merely remove it from the Home Screen. Then download Outlook again from the App Store and add your account. Deleting and reinstalling removes the app’s local data more thoroughly than offloading it, but anything not synced could be lost.

Outlook for iOS does not always expose a separate control called Clear Cache. Reset Account is the first in-app method to try; deleting and reinstalling is the broader fallback. An iOS setting called Offload App is different: it removes the app itself while retaining its documents and data, so it may not clear the stored Outlook data you are trying to refresh.

Common Mistakes

Looking in the wrong place for a cache button. iOS does not have an app-by-app cache-clearing control for Outlook in Settings. Outlook’s account reset is inside Outlook’s own settings, not under Settings > General.
Removing the account before checking drafts. Resetting is different from removing an account, but either process can require a fresh sign-in. Preserve important draft text and confirm that messages have synced before making bigger changes.
Choosing Offload App when you intend to erase local data. Offloading retains app documents and data by design. If you need a clean reinstall, choose Delete App, understanding that local-only content can be erased.
Expecting a cache reset to recover deleted mail. The cache is local app data, not a backup. If a message was deleted from the server or is absent in webmail, resetting Outlook is unlikely to bring it back.
Resetting repeatedly before sync finishes. Re-downloading account information takes time. Give Outlook a chance to finish before trying another reset or reinstall.

Tips

Use Reset Account for a single account that displays stale messages or folders. If several accounts have issues, check the network and Outlook service status before resetting each one.
Connect to Wi-Fi and keep the device charged during a large resync. Outlook may need to retrieve message lists and attachment data again, which can use mobile data and battery.
After the reset, open the folders you rely on and allow their contents to load. Do not judge the result solely by how quickly the inbox appears; older mail and attachments may take longer.
Keep Outlook and iOS reasonably current. App updates can fix sync or sign-in bugs, and updating is a safer early step than deleting the app.
If this is a managed work or school device, follow your organization’s support guidance. Device policies, required authentication, or app protection settings can affect how Outlook reconnects.
Remember that clearing Outlook’s local data is not the same as freeing all storage on the iPhone. Mailbox content remains on the service and may be downloaded again as you use the app.

Troubleshooting

Reset Account is missing: Confirm that you selected the account itself in Outlook’s Settings, rather than opening the iPhone’s Settings app. Update Outlook in the App Store, reopen it, and check the account options again. If the control still is not available, try signing out only if Outlook offers that option and you have verified your sign-in details, or use the delete-and-reinstall fallback.

The inbox is still not updating: Check that the device has internet access by loading a webpage, then test the mailbox in webmail. In Outlook, make sure the account has not prompted for a password, approval, or other sign-in action. For a work account, a changed password or expired organization session may need to be resolved before syncing can resume. If webmail also fails, contact the email provider or workplace administrator rather than repeatedly clearing app data.

Messages or folders are taking a long time to return: Leave Outlook open on a stable connection and allow it to finish syncing. Large mailboxes, slow networks, or many attachments can extend the process. If only older messages are absent, check the account’s web version first; the app may be loading recent content before older items. Avoid deleting and reinstalling while a sync is clearly progressing.

You cannot sign in after resetting or reinstalling: Check the email address and password, then complete any multifactor authentication prompt. A work or school account may require an approved authentication app or device-compliance step. If the password works on the web but Outlook is blocked, ask the organization’s IT support whether its mobile access policy needs attention.

The app still crashes or shows an error: Restart the iPhone or iPad, install available Outlook and iOS updates, and try again. If the issue affects only one account, remove and add that account only after protecting unsent content and confirming that you can authenticate. If Outlook fails with multiple accounts or immediately after reinstalling, contact Microsoft Support or your organization’s administrator and include the iOS version, Outlook version, and the exact error text.

Frequently Asked Questions

Does Reset Account delete my emails?
It refreshes Outlook’s local account data; it is not intended to delete mail stored on the server. However, drafts or other content that exists only on the device may not be recoverable, so verify important items first.

Is there a Clear Cache button in Outlook for iOS?
There may not be a separately named cache control in your version. Use the account’s Reset Account option to refresh local data. If it is unavailable or the problem persists, deleting and reinstalling Outlook is the fuller reset.

Will clearing the cache free up iPhone storage?
It may remove some locally stored data, but the amount varies. Outlook can download account information and attachments again, so storage use may increase as you reopen messages. For a specific storage problem, check Settings > General > iPhone Storage before and after.

Should I offload Outlook or delete it?
Try Reset Account first. Offloading keeps the app’s documents and data, so it is not the best choice when the goal is to erase Outlook’s local data. Delete App removes the app and its local data, but could erase anything that was never synced.

Does this clear Outlook cache on both iPhone and iPad?
Yes, the in-app Reset Account approach is similar on both. The storage menu may be labeled iPhone Storage or iPad Storage, and screen layout can vary by iOS version and device.

Will I need to enter my password again?
Possibly. Outlook may retain your sign-in, but a reset or reinstall can prompt you to authenticate again, including multifactor approval. Make sure you can complete that sign-in before removing the app.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

Spotted an error in this guide? Let us know.