Do you have a or a header from that file you want me to help identify?
Before you double-click, remember that .txt files are generally safe, but filenames can be deceptive. Ensure it isn't actually Crypto.txt.exe .
If this is your file, here is a pro-tip:
The "mail" prefix suggests it’s used for encrypting email communications (Pretty Good Privacy).
A block of "gibberish" text starting with -----BEGIN PGP MESSAGE----- .
If the file contains a block of scrambled text, you need the right "key" to read it.