PSA: Apple Mail Bugs Can Lead to Data Loss in macOS Catalina

Michael Tsai, the developer of EagleFiler and the SpamSieve plug-in for Apple Mail on Mac, has written a blog post warning macOS users about potential data loss in Mail when upgrading to macOS Catalina 10.15.0 (build 19A583).According to Tsai, he's heard from several users that updating Mail's data store from Mojave to Catalina sometimes says that it has succeeded, when in fact on closer inspection it turns out that large numbers of messages are incomplete or missing entirely.
In addition, users