Cannot change archive folder gmail on iPhone Since yesterday I inadvertently deleted an important email (it's waaaay to easy to swipe left too much and delete the mail), I changed the default setting to "archive" instead of delete. But since I want to be able to delete those email from my phone, I created a folder called "To Be deleted" on my gmail account, that I can then empty safely from my computer.

The only thing left to do is to change the default archive folder from "All mail" to the new folder I created, so that I can mark the emails I want to delete from my iPhone and then do so securely from my computer; but when I do this from my iphone the setting does not get saved. In  particular I go to Mail -> Gmail account -> Advanced setting and there i change the "archive folder", but as soon as I leave that screen the change is reverted back.

What is causing this / what should I do now?
This seems to be a bug with "Google" mail accounts in iOS.

I was able to solve this by not showing the "All Mail" label in IMAP in the Labels settings in GMail.

You can then select a different folder as the archive folder in the Mail app. The Mailbox list will still show it as "All Mail" but it is actually your chosen folder.