Common Microsoft 365 / Exchange Email Errors and How to Fix Them
This guide outlines some of the most common issues you may encounter when using Microsoft 365 or Exchange email in Outlook or on mobile devices, along with suggested solutions.
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1. Cannot Receive Email (Inbox Not Updating)
Possible Causes:
- Outlook not connected to Exchange Online
- Mailbox full
- Cached Exchange Mode issues
Solution:
1. Look for “Disconnected” or “Working Offline” in Outlook’s status bar — reconnect if needed.
2. Check mailbox size by logging into Outlook on the Web (OWA) at outlook.office.com. (for Hosted Exchange users, try logging into https://x.twilightit.com/mail)
3. If using Cached Exchange Mode, try disabling and re‑enabling it in Outlook settings.
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2. Password Prompt Keeps Appearing
Possible Causes:
- Outdated stored credentials in Windows Credential Manager
- Recent password change not updated in Outlook
- Multi‑Factor Authentication (MFA) required
Solution:
1. Remove old credentials: go to Control Panel > Credential Manager > Windows Credentials and delete entries for Outlook/Office365.
2. Re‑enter your new password in Outlook.
3. If your organization uses MFA, ensure you have the Microsoft Authenticator app set up.
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3. Outlook Stuck on “Trying to Connect”
Possible Causes:
- Network connectivity issues
- Autodiscover misconfiguration
- Firewall or proxy blocking Microsoft services
Solution:
1. Test your connection by logging in at outlook.office.com.
2. Restart Outlook and your computer.
3. Check firewall or VPN settings to ensure Office 365 services are not being blocked.
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4. Emails Going to Junk/Quarantine
Possible Causes:
- Microsoft 365 filtering flagged the message
- Safe senders list not updated
Solution:
1. Check the Junk Email folder in Outlook and the Quarantine at security.microsoft.com/quarantine.
2. Mark messages as Not Junk or release them from quarantine.
3. Add trusted senders to your Safe Senders list in Outlook or Microsoft 365 Security settings.
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5. Shared Mailbox Not Appearing
Possible Causes:
- Permissions not assigned correctly
- Mailbox not auto‑mapped
Solution:
1. Confirm with your administrator that you have been granted Full Access and/or Send As permissions.
2. If auto‑mapping fails, add the mailbox manually in Outlook under Account Settings > More Settings > Advanced > Add Mailbox.
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6. Synchronization Issues on Mobile Devices
Possible Causes:
- Native mail app not fully compatible
- Device not updated
- Incorrect account type chosen
Solution:
1. Use the Microsoft Outlook app instead of the default mail app for best compatibility.
2. Make sure your device is up to date.
3. When adding the account, always select Microsoft Exchange / Office 365.
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Summary
Most Microsoft 365 and Exchange issues come from authentication problems, outdated credentials, or misconfigured settings. Checking connectivity, updating your password, and using Outlook or the official Microsoft apps will resolve most issues quickly.