Catalina issue: Mail can lose email and data when upgrading macOS

If you are about to upgrade your Mac to macOS 10.15 Catalina, you should definitely make a backup in preparation. Because when you update your Apple Mac to the new operating system, it can happen that some or all of the emails in the Mail app are lost. And even if the emails are picked up, they can be incomplete. Details about the problem and possible solutions can be found in this little guide.

After Catalina upgrade, Mail shows no or incorrect emails

This problem isn't all that new, but it's quite annoying when you work on a Mac. After all, many users depend on smooth e-mail traffic. If all messages are no longer available or no longer available after upgrading the Mac OS, valuable hours are lost in solving the problem. The developer Michael Tsai, among others, points out the errors and problems with the Apple mailing client in his Blog to (translated):

• When updating the mail database from Mojave to Catalina, you may sometimes see a message stating that it was successful, but a large number of messages are missing or incomplete
• Moving between mailboxes - both via drag-and-drop and AppleScript - can result in blank messages (headers only) on the Mac. If the message was moved to a server mailbox, other devices will display the message as deleted. And sometimes they synchronize with the first Mac in such a way that the message disappears there too.

Solution in the collective article on problems with macOS 10.15 Catalina

Here in the blog you will find a collective article on the currently known or most frequently documented problems that can occur after a Mac upgrade from Mojave to Catalina. I try to keep this post up to date and quickly incorporate new problems and proposed solutions. There are currently three entries for problems with mail under macOS Catalina:

• Mail app freezes or freezes under macOS Catalina
• E-mails and e-mail content are not (correctly) displayed after Catalina upgrade
• After the Catalina upgrade, no mails can be received or sent

For further coordination in the article, please use the table of contents "Chapter in this article" attached at the top. This allows you to quickly and easily jump to the desired subheading and the information below. I try to activate and answer comments and questions as soon as possible - but this can take a while depending on the volume;)

Jen Kleinholz( Founder & Sir Apfelot )

Jens has been running the blog since 2012. He acts as Sir Apfelot for his readers and helps them with technical problems. In his spare time he rides electric unicycles, takes photos (preferably with the iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions to current bugs.