Warning: macOS Catalina Upgrade is Causing Mail Data Loss for Some Users

The upgrade to macOS Catalina is causing Mail data loss for some users, according to Michael Tsai, developer of the popular SpamSieve plug-in.

According to Tsai, he's been contacted by numerous users who report that after updating from Mojave to Catalina large numbers of messages are missing or incomplete. Additionally, moving messages between mailboxes via drag-and-drop or AppleScript can also result in blank message (only headers) on Mac. If those messages are moved to a server mailbox, other devices see them as deleted and then sync that back to the original Mac where they disappear as well.

Tsai is advising users to hold off on updating to Catalina if they haven't already.


I don’t know whether these are due to Mail bugs or to other factors such as problems on the Mac or with the mail server. But my advice is to hold off on updating to Catalina for now.

This bug is especially concerning for a few reasons: users may not even notice that anything is wrong, it gets synced to the server and then propagates to other Macs and iOS devices, and backing up and restoring is difficult.

Making a backup is difficult because, even if you set the preference, Mail no longer automatically fully downloads all messages. So the backup of the local data will necessarily be incomplete. (See EagleFiler’s Importing Attachments instructions for more about this. I’m happy to have most of my mail archived outside of Mail.)

Restoring a backup is difficult because Mail data is constantly changing. There is no straightforward way to merge restored data in with messages received since the last backup, and also with the live data on the server.


You can learn more about the problem at the link below. If you've upgraded to Catalina, take a scan through your mailboxes and make sure that you don't have any blank messages. Let us know if you've experienced this issue in the comments!

Please follow iClarified on Twitter, Facebook, or RSS for updates.

Read More