In some cases, there might be outages or network-related issues, such as problems with a VPN. Mail flow issues can also arise out of other circumstances, such as a user having a mailbox in both Exchange Online and Exchange on-premises. 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. Sometimes an error appears in the Mail and Calendar apps when the apps try to sync new email or microsoft 365 error resolution calendar events. These syncing problems usually happen because of issues like a damaged Outlook profile, poor internet connection, or a corrupted OST file.

Now, let’s look at how to fix these issues step by step. Your trusted tech help & troubleshooting hub. If microsoft 365 error resolution the error occurs during a Windows update, the Windows Troubleshooter can help identify and fix the problem.

Try removing and re-adding the problematic calendar to reset the connection. If none of these steps work, consider clearing your Outlook cache or running the calendar repair tool to fix any underlying data issues. Outlook calendar synchronization ensures that your schedule remains up-to-date across all your devices and platforms. Unfortunately, sync issues are more common than one might expect, leading to missed appointments, scheduling conflicts, and unnecessary stress.

IT teams should build a plan to tackle these threats and make sure users are aware of the security concerns. If none of these steps work, the issue might be on the server side, which can make the troubleshooting process more complex. Admins must think about the nature of the problem and which users it's affecting to find the source. For example, ActiveSync might not be enabled, or there might be a problem with the ActiveSync certificate settings. In some cases, IT might be able to track down a problem by examining the Exchange logs.

To do this, navigate to Control Panel and click on “Programs and Features”. If you see multiple versions of Office installed, right click the version you are NOT using, and select “Uninstall”. This may require your computer to restart in order for changes to take effect. The first step is to ensure you are signing in with the correct account. If you receive a message “We couldn’t find any Office products”, you are very likely signing in with the wrong account. Try signing in with all of your personal email addresses in case you purchased Office with a different email address in your past life.

Regardless of their mailbox size, Microsoft set a default OST size for a reason, while it can be changed, that doesn’t mean it should. 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.” Check with your email provider for instructions about how to create an app password for your email account.

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.” 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. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.

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.

Google Calendar may be working correctly, you’ve just not selected the calendar. If this doesn’t work, the only way to make it work is to use a third-party calendar automation tool like OneCal. Reconnecting imported calendars (Outlook, iCloud, or Google Calendars) using the Google Calendar app on your iPhone or iPad is not possible.

First, ensure you have the necessary permissions to view and edit the calendar in question. Check your send/receive settings to make sure Outlook is set to update frequently enough. Verify that you’re not in offline mode and that your internet connection is stable. If you’re using a shared calendar, ask the owner to re-share it with you, as sometimes permissions can become corrupted.

Our clients range from large national nonprofits to 1- and 2-person for-profit consultancies. VPNs often trigger security measures on the website you’re trying to log into, preventing access. A password manager (like Bitwarden) helps avoid errors caused by copying, pasting, and manually entering passwords. Look for a “reset your password” or “forgot password” link somewhere around the username or password box on the login page. Follow the instructions to reset your password and try logging in again. You can try to sign in again later, or ask the developer to increase this app's sign-in rate limit.