Working with a large amount of email address lists with duplicate addresses

Hi, there!

I have a spreadsheet with 15 columns of email addresses. The top row is the name of the lists, with all of the email addresses in that list running down the columns. There are a ton of duplicate email addresses and I'm trying to see if there is a trend in which lists contain the duplicates. Ideally I'd like to organize by email address, with the lists that the address appears on in the columns next to it. Can anyone point me in the right direction on how to do this? There are so many duplicates that highlighting the duplicate values isn't working.

thank you!
Sara

for quick attempt (would be much easier if you posted the file! !) but I would extract out the domain name "@????". For example make a new column for DomainNames and then sort on that and also the full email addresses....then you will have order and semblance to see what is duplicated. Can also use Conditional Formatting or a formula that compares the email address in Row 1 to email address in Row 2....copy formula down. ** display/attach file it would be much easier to show

thank you for your help!! I can't attach my file because it's sensitive info but here is an example of what I'm trying to do:

example.jpg

thank you for your help!! I can't attach my file because it's sensitive info but here is an example of what I'm trying to do:

Attachment 492694

Put the data in a Table, then create a Pivot Table out of it. Use format below
List Name
List1 Cersi
: :
List1 Tyrion
List2 Arya

is there a tutorial you could point me toward or maybe elaborate? That is pretty advanced for me!

I'm not sure I see why you would like data in your representation....I created something which may be helpful or as helpful as I can be without data.
When I look at my results, I can tell that ayra is in List2 only; bran is in list2 and List4...etc. I don't understand your 'results' format, but I believe my method may solve your issue.

(if you sent your 'sensitive data' with changed info (Ex. change/replace email addresses to different characters: all 'a' changed to 'l'; all 'b' to 'w' - it would change sensitive to garbled characters)