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> 1. Old bugs are not fixed. If Apple would open source some of its OS apps, this would probably be a non-issue, I could see people putting in bugfix PRs the second Apple chooses to open source their core apps. I don't see them doing this any time soon sadly, but it would make macOS much more stable, and probably secure. The more I have thought about my views on Open Source vs Commercial software, I strongly feel tha…
Mail.app alone had enough issues and missing features to sustain an entire cottage industry, and would be one app I would certainly like to contribute to. But it shall never come to pass.
I use mail.app daily across phone, iPad and Mac - it's "fine" but I'd really love it to get some investment.