Resolve sync issues in Mail and Calendar apps in Windows 10

Turn off Windows Defender Security Center

Windows Defender Security Center is free security software that's included with Windows 10. If you haven't installed alternative security software, you should temporarily turn off Windows Defender Security Center.

1. Go to Start and open Windows Defender Security Center.

2. Select Fire and network protection.

3. Choose a network profile and turn off Windows Firewall for that profile. Repeat this step for each profile.

4. If you can now sync your email, you'll need to allow the Mail and Calendar apps through the firewall. Follow the steps below.

IMPORTANT: Make sure to repeat the steps above reenable the firewall for each network profile.

Allow Mail and Calendar apps through Windows Firewall

If you can sync your email when the firewall is turned off, you'll need to allow the Mail and Calendar apps through the firewall.

1. Go to Start and open Windows Defender Security Center.

2. Select Fire and network protection > Allow an app through firewall > Change settings.

3. In the list of allowed apps and features, select the check box next to Mail and Calendar, and select the check boxes in the Private and Public columns.

4. Select OK.

Turn off third-party security software

Third-party firewalls or antivirus software might prevent you from syncing your email and calendar events. Although we don't recommend permanently turning off security software, temporarily turning off the software will let you determine if it is preventing you from syncing your email or calendar events. Check the software documentation to learn how to temporarily turn it off.

WARNING: If you disable your antivirus software, don't open any email attachments or click any links in messages from people you don't know.

Remove your account and add it again using advanced setup

If you still can't sync your email after removing your account and adding it again, you might need to add the account using advanced setup. For more information, see Add an account using advanced setup.

Collect the required information from your email provider

Before checking your advanced settings, you'll need to look on your email provider's website, or contact your email provider, to determine the correct server settings. You'll need the following information:

• Incoming and outgoing email server address

• Incoming and outgoing email server ports

• Does the outgoing server require authentication?

• Is the same username and password used for sending email?

  If the username and password are different, make sure you have the correct username and password.

• Does the incoming server require SSL?

• Does the outgoing server require SSL?

• Contacts server (if applicable)

• Calendar server (if applicable)

Check advanced mailbox settings

1. Go to Start and open Mail.

2. At the bottom of the left navigation pane, select .

   

3. Select Manage Accounts and select your email account.

4. Select Change mailbox sync settings > Advanced mailbox settings.

5. Confirm that your incoming and outgoing email server addresses and ports are correct.

6. Unselect the check box next to Outgoing server requires authentication if your provider doesn't require authentication.

7. Unselect the check box next to Use the same name and password for sending email if your provider requires separate authentication for sending email, and provide the outgoing server username and password.

   : If applicable, change the following settings as well:

   • Select the check box next to Require SSL for incoming email if your provider requires SSL for incoming email.

   • Select the check box next to Require SSL for outgoing email if your provider requires SSL for outgoing email.

   • Confirm that your Contacts server and Calendar server addresses are correct.

If you're using an Exchange account that requires advanced settings, you'll need to remove the account and add it again using advanced settings. To add the account using advanced settings, see Add an account using advanced setup.

Your account settings are out of date

The most common cause of an out-of-date account is an incorrect password. In the notification bar at the top of the app, select Fix account. If your password is incorrect, you'll see a message asking you to update your password. Enter the new password and select Done.

If your password isn't the problem, you might have a certificate error. If so, you'll see a message that says, "There is a problem with the server's security certificate. The security certificate is not from a trusted certifying authority."

This error often happens when you don't use SSL to secure your email account. To fix this error, follow the steps below:

1. At the bottom of the left navigation pane, select .

   

2. Select Manage Accounts and select your email account.

3. Select Change mailbox sync settings > Advanced mailbox settings.

4. Confirm that your incoming and outgoing email server addresses and ports are correct.

5. Select the check box for Require SSL for incoming email and Require SSL for outgoing email and then select Done > Save.

This device doesn't meet the security requirements set by your email administrator

If you receive this error, see the article about device security requirements for troubleshooting steps.

0x80072726

An error 0x80072726 might be due to third-party firewall or antivirus software. Although we don't recommend permanently turning off security software, you can go to the software manufacturer's website to see if they have workaround steps, or you can temporarily turn off the software to see if that fixes the issue. If so, contact the manufacturer's technical support to find a way to access your email without disabling their software.

Send us your feedback

We value your opinion. If there's a feature you think is missing from the Mail and Calendar apps, or if a feature in isn't working properly, you can provide feedback directly to the Mail and Calendar team.