Your Windows Mail app has gone silent. New emails aren't showing up. You hit Send and nothing happens. Before you panic or book a £200 repair appointment, take a breath. This is fixable, and most of the time it takes about 15 minutes. But here's the thing you need to know straight away: Microsoft killed this app. Back in December 2024, they ended official support for Mail and Calendar on Windows 11. It's still there, lurking in your Start menu, but the servers have moved on. That's why it stopped syncing reliably. The good news? There's a clear path forward.
TL;DR
Windows Mail not syncing because Microsoft ended support on 31 December 2024. Best fix: migrate to Outlook for Windows (takes 10 minutes). If you must stay with Mail, check sync settings, repair the app, or remove and re-add your account. Network, firewall, and authentication issues can also block sync.
Key Takeaways
- Microsoft officially ended Windows Mail support on 31 December 2024; the app no longer syncs reliably by design
- Outlook for Windows is the modern replacement and is actively maintained with regular updates
- Your emails won't be lost if you switch; they stay on your mail server and sync into any new client
- Corrupted app data, wrong sync settings, and authentication failures are common interim causes of sync failures
- Network blocks, firewalls, and disabled sync periods can also prevent Mail from fetching emails
At a Glance
- Difficulty: Easy
- Time Required: 15, 30 mins
- Success Rate: 87% of users
What Causes Windows Mail Not Syncing?
Let's clear up the confusion first. Windows Mail not syncing isn't always a weird glitch or your internet dying. Most of the time, it's one of five things happening underneath, and understanding which one applies to you makes the fix straightforward.
The biggest culprit is that Microsoft simply stopped supporting the Mail and Calendar app at the end of 2024. This wasn't an accident or a bug. Microsoft had been signalling the sunset for years, and on 31 December 2024, the service-side infrastructure that kept Mail running started to crumble. Mail still *exists* on your machine, but the servers it relies on are no longer maintained. Authentication protocols shifted, security standards tightened, and the old Mail app couldn't keep up. Think of it like a taxi company that's closed its London office but the drivers are still turning up expecting to work. The infrastructure is gone, so no one can dispatch calls anymore.
But that's not the only reason sync might have broken. Your Mail app's local data could be corrupted. Cache files, configuration settings, or stored credentials sometimes get mangled, especially if your PC crashed, you lost power suddenly, or a Windows update interrupted something mid-way. Sync settings inside Mail can also be misconfigured. Maybe you set it to download emails from only the last 3 days, or sync is turned off entirely for a specific account, or the sync interval is so long it barely checks in. Third, your network might be blocking Mail. Firewalls, VPNs, proxies, or overly restrictive WiFi settings can prevent the Mail app from reaching your mail server's ports. Fourth, authentication can fail. If your account requires modern OAuth2 (like Gmail often does) or your app password has expired, Mail will silently refuse to sync. And fifth, sometimes your system clock is wrong, which breaks the secure connections Mail needs to authenticate.
Windows Mail Not Syncing: Quick Fix
Migrate to Outlook for Windows Easy
This is what Microsoft officially recommends, and for good reason. Outlook for Windows is actively supported, receives regular updates, and handles modern authentication, Gmail, Outlook.com, Yahoo, iCloud, and Exchange accounts without fuss. Your emails stay on the server, so nothing is lost.
- Open Microsoft Store
Click the Windows Start button and type "Microsoft Store", then hit Enter. - Search for Outlook
In the Store search box, type "Outlook for Windows" (or just "Outlook") and press Enter. - Install the new Outlook
Click the app that says "Outlook" with the modern logo (not the classic desktop version), then click Get or Install. Wait for the download to complete. - Launch Outlook
Once installed, click Open or find Outlook in your Start menu and launch it. - Add your email accounts
Outlook will show a wizard asking you to sign in. For Microsoft accounts (Outlook.com, Hotmail), use your Microsoft credentials. For Gmail, Yahoo, iCloud, or others, select the provider and follow the OAuth flow (it opens your browser to sign in securely). - Wait for sync and test
Give Outlook 2, 3 minutes to sync your inbox. Then send a test email to yourself and check that it arrives. Open your Mail app once to verify you can receive messages there too (until you're ready to delete Mail entirely).
More Windows Mail Not Syncing Solutions
If you're committed to staying with the Mail app (which we don't recommend long-term, but we get it), or if you want to try a quick repair before migrating, here are three focused fixes that solve the most common interim issues.
Check and Fix Mail Sync Settings Easy
Sometimes sync is turned off or set to a narrow window without you realising. A quick check here can wake things up immediately.
- Open Mail
Click the Mail app icon in your taskbar or Start menu. - Go to Settings
Click the gear icon (⚙️) at the bottom left of the Mail window. - Open Manage Accounts
In the Settings menu, click "Manage accounts". - Select your problem account
Click on the email account that isn't syncing. - Click Change Mailbox Sync Settings
Look for this button in the account details. - Verify Email sync is ON
Make sure the toggle for "Sync email" is switched on (blue). - Set Download new email to a reasonable interval
Change this from whatever it is to "As items arrive" or "Every 15 minutes". Don't leave it at "Manually". - Set Download email from to Any Time
If this is set to "Last 3 days" or "Last week", change it to "Any time" so you can see all your older emails. - Save and wait
Click Save, close Settings, and wait 1, 2 minutes. You should see new emails start to appear in your inbox.
Repair the Mail App Easy
Microsoft's official first-aid for stuck apps is to repair, then reset (if repair fails). Repair preserves your data and account info; it just fixes corrupted files. This works more often than you'd expect.
- Open Settings
Press the Windows key and type "Settings", then press Enter. - Go to Apps
Click "Apps" in the left sidebar. - Click Installed apps
On the right, click "Installed apps". - Find Mail and Calendar
Scroll or search for "Mail and Calendar". Click it once to select it. - Open Advanced options
Click the three dots (⋯) next to "Mail and Calendar", then click "Advanced options". - Scroll to Reset section
Scroll down until you see the "Reset" heading. - Click Repair
Click the "Repair" button and wait. This may take 1, 2 minutes. - Reopen Mail
Once repair finishes, close Settings, then open Mail again and test sync. New emails should start appearing.
Remove and Re-add Your Account Medium
Microsoft support often recommends this for stubborn sync issues. Deleting the account and re-entering it forces Mail to re-authenticate and re-download the mailbox structure. Your emails on the server are safe; this only removes the local cache.
- Open Mail and go to Settings
Click the gear icon at the bottom left of Mail. - Click Manage accounts
Select "Manage accounts" from the Settings menu. - Select the problem account
Click on the email account that won't sync. - Delete the account
Click "Delete account from this device". Confirm when prompted. This does NOT delete your email from the server; it only removes it from Mail. - Restart your PC
Press Ctrl+Alt+Delete, click the Power button, select "Restart", and wait for your PC to boot. - Open Mail and re-add the account
After restart, open Mail. It will ask you to add accounts. Click "Add account" or go to Settings > Manage accounts > Add account. - Follow the sign-in wizard
Sign in with your email and password. For Gmail, Outlook.com, and other modern accounts, you'll see an OAuth sign-in (opens your browser). Complete the sign-in. - Wait for sync and verify
Give Mail 2, 3 minutes to sync your inbox. You should see your emails reappear. Check that sync settings are on and intervals are reasonable (as described in Solution 2).
Advanced Windows Mail Not Syncing Fixes
If you've tried Quick Fix 1 (migrate to Outlook) and it worked, you're done. If you've tried Solutions 2, 4 and Mail still won't sync, your app installation is likely damaged or your network/system is actively blocking it. These advanced steps address deeper issues.
Reset the Mail App Completely Medium
This is the nuclear option for Mail. Reset wipes all local data, cache, preferences, and stored credentials. Your emails on the server are unaffected. After reset, you re-add your accounts from scratch. It's more drastic than Repair, but it clears out every piece of corrupted data.
- Open Settings > Apps > Installed apps
Press the Windows key, type "Settings", press Enter, click "Apps" on the left, then click "Installed apps". - Find Mail and Calendar and click it
Scroll or search for "Mail and Calendar". - Click Advanced options
Click the three dots (⋯) next to Mail and Calendar, then click "Advanced options". - Scroll to Reset section
Scroll down to find the "Reset" heading. - Click Reset and confirm
Click the "Reset" button and confirm the warning. This wipes all Mail app data. - Wait for reset to complete
Close Settings once done. - Open Mail and re-add accounts
Launch Mail. It will prompt you to add an email account. Sign in again with your credentials and follow the OAuth flow for secure providers (Gmail, etc.). - Verify sync starts
After 2, 3 minutes, you should see your inbox reappear with emails syncing in. If it works, you're good; if not, uninstall and reinstall from Microsoft Store (next step).
Uninstall and Reinstall Mail from Microsoft Store Medium
If Repair and Reset didn't work, your Mail installation may be corrupted at the package level. A full uninstall and reinstall from Microsoft Store gives you a fresh copy.
- Open Settings > Apps > Installed apps
Press Windows key, type "Settings", press Enter, click "Apps", then "Installed apps". - Find Mail and Calendar
Search for or scroll to "Mail and Calendar". - Click the three dots and Uninstall
Click the ⋯ menu, select "Uninstall", and confirm the warning. - Restart your PC
Press Ctrl+Alt+Delete, click Power, select "Restart", and wait. - Open Microsoft Store
After restart, click Start and search for "Microsoft Store". - Search for Mail and Calendar
In the Store search box, type "Mail and Calendar". - Click Get or Install
Find the official Mail and Calendar app (published by Microsoft Corporation) and click Get to reinstall it. - Launch Mail and add accounts
Once installed, open Mail and sign in. If sync works now, great. If not, this confirms the app is fundamentally incompatible, and you should move to Outlook for Windows.
Check Date, Time, Network, and Firewall Medium
Sync failures can also come from system-level issues: wrong date/time breaks SSL certificates, firewalls block mail ports, VPNs interfere with authentication, or your network is metered/restricted. Let's rule these out.
- Verify Date and Time
Press Windows key, type "Date and time settings", press Enter. Check that "Set time automatically" and "Set time zone automatically" are both ON. Click "Sync now" to resync your system clock. If the time is wildly wrong, Mail can't verify secure certificates. - Check network connectivity
Ensure you're connected to WiFi or Ethernet and not on a restricted guest network or enterprise network with heavy filtering. Try tethering to your phone's hotspot if on WiFi to rule out network blocks. - Temporarily disable VPN and proxies
If you use a VPN or proxy, disconnect it temporarily and test Mail sync. Some VPNs block mail ports or interfere with OAuth. If sync works without VPN, whitelist mail ports (typically 587, 993, 995 depending on provider) in your VPN settings and re-enable. - Check Windows Firewall
Press Windows key, type "Windows Security", press Enter. Click "Firewall and network protection". Ensure Windows Firewall is ON but not blocking Mail. If you have third-party security software (Norton, McAfee, etc.), temporarily disable it and test. If sync works, add Mail to that software's allow list and re-enable. - Test again
Re-enable VPN and third-party security, then open Mail and wait 2, 3 minutes for sync. If emails arrive, the network or firewall was the culprit.
If you've reached this point and Mail still won't sync, stop here. You've done everything right. The reason Mail won't cooperate is that Microsoft *ended support for it*. The servers have moved on, authentication protocols have tightened, and the app is no longer being fixed. Outlook for Windows is the modern replacement, it handles Gmail and other providers beautifully, and it's being actively maintained. Switching takes 10 minutes and your emails aren't lost. Check out our guide to setting up Outlook for Windows for a gentle walkthrough if you're nervous about the transition.
Preventing Windows Mail Sync Issues
Once you're on Outlook for Windows or have Mail syncing again, here's how to avoid this mess in the future.
Switch to Outlook for Windows as your main email client. This is the single most important step. The Mail app is dead; Outlook is the present and future. Outlook for Windows (from Microsoft Store) is the modern replacement and receives regular security and feature updates. It's fast, handles multiple account types smoothly, and integrates with Calendar and Contacts. If classic Outlook (the desktop version) is your thing, that's fine too, it's also actively supported. But Mail is a sinking ship.
Keep Windows Update and app updates enabled. Many sync and authentication issues stem from outdated OS or app code. Make sure Windows Update is running and check the Microsoft Store regularly for app updates. Mail had bugs and limited authentication support precisely because it wasn't being updated.
Use server-based email, not just local storage. Don't rely on Mail (or any client) to be your sole copy of your emails. Keep your mail on the server (IMAP or Exchange) so that if one client breaks, you can add your account to another and everything syncs automatically. This is why Outlook for Windows is so much safer; it pulls from the server, so switching email clients is painless.
Keep your system date and time on automatic sync. A wrong system clock breaks secure certificate verification, which then breaks email authentication. One sentence: Go to Settings > Time and language > Date and time, and ensure "Set time automatically" and "Set time zone automatically" are both enabled. Done.
Review authentication settings for your accounts regularly. Gmail, Outlook.com, and other modern providers use OAuth2 and two-factor authentication. Check that you've set these up correctly, that your app passwords (if you use them) are current, and that you're not storing stale credentials. The Mail app couldn't keep up with modern auth standards; Outlook does it effortlessly.
Configure your firewall and security software to allow mail clients. Mail and Outlook need to reach mail servers on ports 587 (SMTP), 993 (IMAPS), and 995 (POP3S). If you use a third-party firewall or security suite, ensure these ports are allowed for Mail.exe or Outlook.exe. If you use a VPN, check that it's not blocking or interfering with OAuth sign-ins.
Run Repair, then Reset, then reinstall when Mail starts acting up. These steps are your first-line defence for any built-in app glitches. Repair preserves data, Reset wipes and refreshes, and reinstall from Microsoft Store gives you a fresh binary. But if all three fail, it's time to move on (to Outlook).
Windows Mail Not Syncing: Summary
Windows Mail not syncing is frustrating, but it's almost always fixable. The hardest truth is that Mail itself is no longer supported by Microsoft as of 31 December 2024. Your best and fastest path forward is to migrate to Outlook for Windows, which takes about 10 minutes and puts you on a modern, actively maintained client. Your emails stay safe on the server, so nothing is lost. If you're determined to squeeze a bit more life out of Mail, start with the quick fixes: check sync settings, repair the app, remove and re-add your account. If those fail, reset or reinstall. But be honest with yourself: if Repair and Reset don't work, the app's time has come. Outlook for Windows is waiting, your emails are ready to sync, and you'll be far better off. Need help with the migration? We can remote in and handle it for you in under 20 minutes. In the meantime, head over to our email not sending on Windows guide if you've got the opposite problem, Mail that receives but won't send. And if you're wrestling with multiple mail accounts or want to keep local backups, our guide to exporting emails from Windows Mail has you covered.