If you are using iMail and emails in folders stored on the Mac "disappear", you may simply need to reconnect those iMail folders with the emails again. Re-connecting the folders with their data allows those emails to be listed and accessible.
Re-Connecting Mac iMail Folders After Emails Disappear
- Navigate to the mail data folder for the affected user profile
- Open Finder
- Click Go and select "Go to Folder"
- Type "~/Library/Mail"
- The ~ is a placeholder for the current user profile.
- If you are logged in as a different user than the one experiencing the issue, type out the user name in place of the ~ symbol.
- Open the latest mail folder (in this example, V4 instead of V2)
- Make sure the iMail application has been exited
- Open the MailData folder
- Select all files with the name "Envelope" and move them to the desktop or another folder (this is just a precaution in case they need to be restored which is unusual)
- Open iMail and wait for the index files to rebuild
- Depending upon the number and size of emails within each folder, this process can take some time
- Click on folder names located on the Mac and emails should being to appear
- Once finished, all emails previously located in these folders should be listed
- Continue using iMail as before!
As always, knowing how to recover from the unexpected can be the key to getting those items you need back the way they belong!