Remove duplicate emails from gmail all mail that have been moved to mailbox.org

Questions
1

I have moved my emails that were stored in Gmail over to Mailbox.org using thunderbird.

But before that I have my emails in gmail folders (They call them labels)

However, when I look in inbox in gmail there are only a few emails but if I go to all mail, there are some additional emails that I had moved from Gmail to mailbox.org

So when I look at emails in mailbox.org and all mail in gmail there are some that are the same. Is there a tool or way of scanning all mail in gmail in thunderbird and compare with mailbox.org

Or is it a case of having to go through and manually sort?

2

Manually deleting these emails will take a lot of time so you can use a third party application to mass delete emails in Gmail using the app. Let me know if you want to know some good options.

3

I’ve used IMAPdedupfor the exact same reason before, and it worked really well.

Make sure you understand the commands and do some dry runs first. You might want to move mails instead of permanently deleting them with this tool.