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. If you have a Google, Yahoo! Mail, iCloud, IMAP, or POP3 account, check the settings in the advanced mailbox settings to make sure they're configured to your email provider's specification. If you're using an Outlook.com, Microsoft 365, or Exchange account, you won't have advanced mailbox settings unless the account was set up using advanced setup. If your problem is how quickly mail populates, change the download preference to headers then full items.

Remove your account and add it again

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. Before you begin, make sure that your device has the latest operating system and app updates. Try the general troubleshooting solutions in Troubleshooting Mail and Calendar apps for Windows 10. If that doesn't solve your issue, try the solutions below.

Allow Mail and Calendar apps through Windows Firewall

Why is Outlook 365 getting emails on my phone but not my computer?

If it is lower than 50 GB, you may have too many sync issues in which case you must delete the cache and re-run the sync, you can clear sync issues and test before deleting the cache. Some of the most common issues users encounter with Outlook FixTechGuide Office 365 support on iOS relate to syncing. Learn how to troubleshoot when the iPhone Outlook app is not syncing. The approach that IT takes to address a syncing problem depends on what type of problem it is. If it's a client-side issue, the admin can usually instruct the user on what steps to take.

Check your security software

To add the account using advanced settings, see Add an account using advanced setup.From there, make sure that the proper calendars are selected.If you haven't installed alternative security software, you should temporarily turn off Windows Defender Security Center.Before you begin, make sure that your device has the latest operating system and app updates.I think Online Archive may be a harder sell but we need to do it anyway.If restarting Outlook or fixing the profile doesn’t work, converting the OST file is often the next step.In some cases, an issue might be related to MDM settings, such as restrictions on Outlook functionality, or user account and mailbox settings in Exchange.If it's a client-side issue, the admin can usually instruct the user on what steps to take.

Check the software documentation to learn how to temporarily turn it off. Firewalls and antivirus software might prevent you from syncing your email and calendar events. When issues occur at the account level, admins should ensure that users are properly logging into their accounts and provide them with instructions as needed. For example, admins might want to check the user's Exchange account settings and whether they can reach Exchange Server.

7 Customer support

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. We're sorry you're having problems with the Mail and Calendar apps for Windows 10. To fix the issue, please try each of the following solutions in order. Why not limit the caching to a more reasonable 1 year, if they need to access things outside of this, they can, they just have to click ‘view messages on server’ to do so. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.

Check the connectivity to your email server

Change the limit to 1 year, wait for the sync, check the size of the OST once Outlook confirms all sync has been completed. Now change the slider to 2 years and follow the same principal. Outlook has a hard limit of 50GB per OST, decrease the period of e-mails that get cached, delete the cache, and re-run the sync.