Be careful what you say. Say.

I’m sorry! unfourtunately you have identical letters. Please destroy the document. Furthermore, check a double use of the E-Mail adress. It may not be the first time with a gmail adress!

Best regards A. Klipstein

p.s. Should I be afraid of something?  What is to be Afraid?  Why do you ask?   To live with fear, something to return to, get rid of, deal with, face and watch.