how do i delete duplicates if the only difference is date

Question

years ago i made a mistake of transfering my email from outlook to gmail, they were both set to forward to eachother so all emails bounced back and forth causing duplicates, i feel i have gotten rid of most but i have two folders left

name 1
name 2

it is possible that name 1 has all the original emails while name 2 only has duplicates, all emails in name 2 are incorrectly dated i want to remove name 2 but i need to make sure that name 2 only has duplicates

how do i only delete duplicates in name 2 comparing to folder name 1 and how do i do a mass duplicate search on my inbox, all duplicates have only one difference and thats the date they were copied.

làm cách nào để xóa các bản sao nếu sự khác biệt duy nhất là ngày