Michael Tsai, EagleFiler developer and Apple Mail’s SpamSieve plug-in on Mac has written the blog notifying macOS users about the data loss in the mail upgrading to macOS Catalina 10.15.0.

On the authority of the Tsai, he’s marked out from macOS users upgrading from Mojave to Catalina bugs appears to be on the Mail. In fact, while upgrading large no of messages are incomplete or missing entirely.

In supplementary, users had complained about a loss of message contents when moving emails from mailboxes. Via Tsai’s post:

Moving messages between mailboxes, both via drag-and-drop and AppleScript, can result in a blank message (only headers) on the Mac. If the message was moved to a server mailbox, other devices see the message as deleted. And eventually this syncs back to the first Mac, where the message disappears as well.

Tsai’s admits that the issues are particular harmful until users realize anything inaccurate in the messages or Mailboxes. After all the data is synchronized to the server, these issues can also spread to other computers and devices, and it is difficult to rely on backups due to the facts that Mail data is continuously changing and difficulties come when merging the restored data with the message received considering the last backup’s.

Although it is better to make backup rather than taking risks while upgrading from macOS Mojave to Catilina 10.15.0. Apple Mail’s File -> Import Mailboxes… menu bar options are used to import mails to Catalina as new mailboxes.

Tsai’s declared that he’s uncertain whether these issues are due to Mail bugs or to other factors. Apple revealed macOS Catalina‌ 10.15.1 beta to developers on Friday but it is not even not known yet whether this version solves the mail bugs issues. Disregarding for the users who rely on Apple Mail’s, Tsai’s advice to “stop updating Catalina for now”.

Are you having the same Mail’s issue in the macOS Catalina 10.15.0?