Yeah. I’ve stopped caring. Apple can’t fix Mail. I assume it’s part of the overall RAM problems that plague iOS 13. I frequently get Safari page reloads with the notice “this page has reloaded because a problem occurred.” I’ve never had that problem in my 16 years of OS X/iPhone usage.
I‘ve been doing a variety of aggressive testing on my 6th Gen iPad since iOS 13.4 and I could almost swear that memory management issues in iOS 13 are partially related to the Mail app (or perhaps iOS 13 subsystems which use the Mail app uses).
I did a compete restore when iOS 13.4 was released and within a day or two I was noticing memory management issues as bad as previous updates, of which Mail and Safari were the worst.
While playing with the Mail app settings, I realized that if I switched my Fetch settings (for getting my Google Mail) from 15 Minutes back to the default of Automatically, the memory management issues on my entire device were reduced dramatically.
I then restored my iPad again and this time decided not to use the Mail app at all but just used Google‘s Gmail app. Again I saw another huge jump in memory management performance, with page reloads occurring way, way less in a variety of apps (Safari, YouTube, etc).
As of right now, my memory management is way, way better then it was but still not as good as it was in iOS 12. This is why I think some subsystem of iOS 13 is corrupted in some.
What’s weirdest of all though is I don’t understand how this issue seems to ramp up over time after an install. For example, if you do a complete restore, Mail and Safari (and memory management in general) are great, seeming to work perfectly in the first few hours. But within two to three days, everything seems to degrade dramatically back to whet they were before the restore.
So what’s going after a restore or initial setup? Something is occurring in the background that is supposed to normally "optimize" the device in some way but whatever the bug is, that optimization process actually degrades the device instead. I would love to know what’s going on in the background in the first few days of a device being setup.