Mail Archiver 5.1.5 fixes a couple of minor bugs including some fixes for Catalina.
- Fixed a problem where the full hard disk access wasn't recognised on Catalina.
- Emails are moved again to the trash for Imap.
- Fixed another problem with the installer on Catalina.
- The wizard no longer gets confused when clicking the app icon.
- The trash mailbox wasn't always recognised for IMAP.
The press is either love, peace and harmony or gloom and doom. They only report the new features of Catalina. But I haven't seen anything about the problems that Catalina has:
- The new "improved" security is just awful. It's only window dressing. For me as developer the security is even more intrusive than before. For you as user this may be a bit different.
- I have never ever before seen a macOS beta with so many bugs. I still can't properly unzip many files without getting an error message. I made Finder crash with selecting a file. The communication between Apple and the developer never was great. During the Catalina beta there wasn't even that. Some bugs were fixed. But I had to check the bugs myself instead of getting a notification from Apple.
- A lot was changed internally. The growing pains of that combined with the new security meant a lot of fun and may cause some rough edges in other apps.
Please update to Catalina with a plan:
- Make sure you have replacements for your 32bit apps or run those in a Mojave VM.
- Most likely all your system utilities will need to be updated to the latest version: Alfred, Find Any File etc.
- Don't update in a hurry.
- Backup! 2 backups are better than one backup. Make sure that your backup app works on Catalina, too.
- Mail Archiver, too, will have to be the latest version.
Tidbits has a more detailed article.