Compare 2 email lists whether the emails already exist or not

Hello,

im new to this forum so i dont know if this is the right subforum.


My task is to find out which of the emails (names) in the first list are already in the second list with the new email provider.
If we look at the examples above jake.miller has got the new email provider. freddy.bane isnt in the second list.
I need to find out who has already got the new email provider and who hasnt't.

Since there are over 1000 Mails i cant do it by Hand.

Is there any solution to this problem?

Thank you