Hi,
I would like to add some kind of feature to my XLS file but have no idea
how.
I have an excel file where i put all e-mail addresses for newsletter. I
gather more information then an email address but this feature is about
that.

All e-mails are row under row in column C. Every new person is added in the
last row (after last person).
Now, I would like the Excel to inform me (msgbox) when i input an e-mail
address which is already in the document (the user registered himself
twice).

I was looking for the solution of my problem for a long time but there is
absolutely nothing what google finds about it.
I would like to have an "E-Mail already exists!" message box when duplicate
email inputed.

I hope someone knows what am i talking about and is able to help me. Thanks
in advance.

Best regards
Byru