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Struggling with Vanishing Appointments and Email Errors in Outlook? Here’s How to Solve Them!
Emails Marked as Spam or Rejected by Strato
Problem: Emails sent from Exchange Online tenants to Strato are rejected as spam with error code 550 5.7.350. Despite proper SPF, DKIM, and DMARC configurations, Strato’s server refuses the emails due to local spam policies.
Solution:
- Modify the email content or sending method as per Microsoft’s Bulk E-mailing Best Practices.
- Contact the recipient’s administrator to whitelist the sender’s domain.
- If issues persist, verify that the sending IP is not blacklisted and consider routing emails through a smart host with IPv4 addresses to bypass potential IPv6-related issues.
Disappearing Appointments in Outlook Calendar
Problem: Users report that recurring appointments vanish from their calendars without manual deletion. In some cases, old appointments are canceled or conflict notifications appear for past events.
Solution:
- Check if a retention policy is causing automatic deletions.
- Disable caching for shared folders in Outlook settings.
- If antivirus software is interfering, adjust its settings to prevent false positives.
- As a last resort, restore missing calendar items from the Recoverable Items Folder.
Missing or Corrupted Email Signatures
Problem: Email signatures disappear or become corrupted after migrating to newer Outlook versions (e.g., Outlook 2024). This may be caused by the Roaming Signatures feature syncing incorrectly.
Solution:
- Disable the Roaming Signatures feature by modifying the registry:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Setup DWORD Value: DisableRoamingSignaturesTemporaryToggle = 1
- Restart Outlook for changes to take effect.
- Recreate missing signatures by copying contents from local storage (%appdata%\microsoft\signatures).
- Use drag-and-drop methods instead of copy-paste to preserve formatting when creating new signatures.
Additional Tips for Troubleshooting
- Regularly monitor DNS settings and email authentication protocols (SPF, DKIM, DMARC) to ensure compliance with security standards.
- Keep backups of critical data such as calendar entries and email signatures to avoid permanent loss during unexpected issues.
- Stay updated on Microsoft’s latest features and changes (e.g., roaming signatures) to proactively address potential problems.
By addressing these recurring problems with targeted solutions, users can restore productivity and ensure seamless communication across Microsoft 365 platforms.