gmailgmail-labels
I had one label on a message, and then I clicked "Remove Label" when that message was selected. Now I can't find that message – it's not in the Inbox, and of course not in the label that I removed from it
Can someone explain to me what I did wrong and where my message is?
All mail in Gmail is in the All Mail label, unless the message is deleted. Even Inbox is just a label. When you add or remove a label, the email is still in All Mail, it just also shows up in the other label if it's labeled.
Note: even All Mail is a label, it just is the only one that can't be removed (except by deleting the message).
As you've discovered, removing a parent label removes all of its child labels as well. This is a design decision and I'll wager that they researched whether more people would expect the children to be removed or moved up one level to the top. I also expect that it's much easier to code. (Can you imagine how complex it would be to manage a four-level deep nested label when you delete a parent at level two?) The warning message could probably be clearer.
As to your second question, un-nesting a label:
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Best Answer
Look in your All Mail folder. Inbox is basically a label just like a custom label you create. When you remove all labels for a message, then it won't show in any of them (obviously), but it lives in the All Mail category. This is also what happens when you archive an email.
You could also do a search for this particular email.