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macrumors bot
Original poster
Apr 12, 2001

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 have reported the loss of message content when moving emails between mailboxes. From 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 warns that these issues are particularly pernicious because users may not realize anything's wrong unless they look at affected messages or mailboxes. Since the data is synced to the server, these problems can also propagate to other computers and devices, and relying on backups is difficult because Mail data is continually changing and there's no easy way to merge restored data with messages received since the last backup.

Despite the latter risk, it's still good practice to make backups, but Tsai notes that Apple Support appears to be erroneously advising users that lost Mail data in Catalina can't be recovered from a Time Machine backup made using macOS Mojave.

According to Tsai, this is not the case: Apple Mail's File -> Import Mailboxes... menu bar option can be used to selectively import them into Mail in Catalina as new local mailboxes.

Tsai says he's unsure whether these issues are due to Mail bugs or to other factors such as problems on the Mac or with the mail server. Apple released macOS Catalina 10.15.1 beta to developers on Friday, but it's still unclear if this version resolves the Mail app bugs. Regardless, Tsai's advice to users who rely on Apple Mail is to "hold off on updating to Catalina for now."

Affected readers can find the full breakdown of the issues here. Have you had problems with Mail since updating to Catalina? Let us know in the comments below.

Article Link: PSA: Apple Mail Bugs Can Lead to Data Loss in macOS Catalina
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Mar 22, 2009
The only way this doesn't still seem to be such a widespread issue (but I've been reading about Catalina's mail issues for months) is that nobody in their right mind would install the very first release of any OS on any production machine. Heck, I installed Mojave on mine for the very first time just a couple of months ago.


macrumors 65816
Aug 8, 2018
Can all the people defending Apple like "it's ok to brick your system it's only beta" now wake up and see Apple has a software development problem that is getting worse and worse

none of them wake up, mostly apple fed trolls.
it’s fascinating how our economy works today, Apple on an all time high. Products are near an all time low.
just overpaid junk and e waste.


macrumors 6502
May 27, 2011
All the bugs in macOS, iOS and iPadOS are making me seriously consider alternatives. I am in the eco system for the short term, but I’m actively trying to switch over to cross platform services and apps so when the time is right, I can move away with the least amount of hassle.

I’ve always been happy paying Apple prices for the service and experience you get with Apple products. However, I use Windows on my gaming PC and it’s rock solid - the latest Android phones look great too and the Note 10 had me drooling for weeks before I decided against based on the ecosystem and camera. And then the Oneplus 7T got released with the amazing price to specs ratio and 90hz screen!

The only reason I’m “stuck” for now is that Banktivity has my data and I use it and it’s great and they refuse to make a cross platform product. However, I’ve been playing around with MoneyWiz and maybe I’ll go to them as I really miss the Thinkpad keyboards, etc


Oct 21, 2008
Time, because it rules EVERYTHING!
Congratulations Apple! I absolutely applaud their efforts in making every single OS they make, no one else made it, have some pretty bad bugs..

it makes their devices such poor value when they continue to rush out their broken software! It’s beyond a joke now when I think back at how manny bugs under Cook we have had, iOS 11 was a pure joke of an OS, iOS 13 has bugs and iPad OS feels like a beta version! Which is a shame because of its potential.
and now Mac OS will delete your emails!

I guess just another reminder that Cook and his team simply do not give a damn about quality control still.

only Apple share holders and blind loyalty Apple fans can defend this behaviour!
I was personally looking forward to iPad OS, such a shame it’s annoying as hell with its bugs. Which I don’t expect to be fixed until iPad OS 14 next year going by Apples history..


macrumors newbie
Oct 12, 2019
Apple missed the chance again for a groundbreaking redesign of the old fashioned email concept. No innovation in the main tools we all use everyday like mail, calender, adressbook and browser. This would really be a reason to stay or even switch to an OS. The first competitor who offers this could count me in.

Also they loose the competition to MS surface while still bringing no grown up laptop functionality to the iPad. This handicapped mouse support is a joke. The whole multitasking gestures are hard to learn.

and last but not least: the MacPro. Who should afford this?? Your pricing is a joke.

„Innovate my a**?“ Yes, you better should start.
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Mar 10, 2009
Waiting for our resident “Keep it up Tim, you’re doing a great job!” lapdogs to chime in defending this garbage. Apple’s QC, especially with regard to OS releases has become atrocious. Sure they release updates, but these problems should not be happening in the first place. Heads should be rolling over these shoddy releases.

But never mind bugs causing data loss. The stock is up and that’s all that matters right?
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Oct 21, 2008
Time, because it rules EVERYTHING!
One would think a trillion dollar company could afford a QA department with people that are actually competent.
That’s why they are worth a trillion dollars... they are cheap on their resources, have everything made for the cheapest price in China, then massively inflate their RRP on products that rarely go on sale. Throw in the odd scandle to up sell new phones and tax dodging and that’s how you become a trillion dollar company.
But remember iOS and Mac OS are made by Apple themselves, and you read beta testers on here claiming how long this or that bug has existed in the beta’s and they report them, yet they are still in the final releases.. I think Apple needs to follow Google’s model, release critical updates at any point in the year, but then I’d suggest major updates once every two years, Apple can save as many penny‘s as they like then on their skeleton software staff, and possibly make products that work.

Most people don’t think about these things, but Apple will force OS upgrades onto all its customers by messages popping up or automatic updates, and then they will see these bugs.. they will certainly care about that!

All in all I fully expect that arrogant hypocrite Cook to get on stage and gloat about how many users have updated to the latest iOS and Mac OS, compared to the competition... conveniently ignoring all the bugs..
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