The cause of the error where calendar entries are missing after removing and re-adding an email account can vary, but here are a few possible reasons:
- Synchronization issue during the switch from POP to IMAP.
- Data file corruption in the Outlook.pst file.
- Human error, such as accidental deletion or overwriting of calendar entries.
- Software conflicts or bugs in the MS Office version.
To address the issue and retrieve your old calendar entries, try the following:
- Check for synchronization or configuration problems: Ensure that your IMAP account is properly configured to sync the calendar data with the server. Double-check the settings to ensure everything is in order.
- Consider data file corruption: It's possible that the Outlook.pst file containing the calendar entries has become corrupted. You can start by running the scanpst.exe tool (Inbox Repair Tool) to repair the file. However, if it doesn't resolve the issue, you can explore other options.
- Explore third-party PST repair tools: There are reputable third-party tools available, such as Stellar Repair for Outlook, Kernel for Outlook PST Repair, and SysTools Outlook Recovery, that specialize in repairing PST files. These tools may provide better chances of recovering your lost calendar entries.
- Restore from a backup: If you have a recent backup of your Outlook.pst file, restoring it can help retrieve the missing calendar entries. It's always a good practice to maintain regular backups of your Outlook data.
Let me know if the above steps worked out for you or if you need any further assistance regarding this.