I know that the password is 9-10 characters long, contains "r", "u", "@" and "." and I know that the password is an email. Is this even worth decrypting? Or it is impossible to get the password just based on this information?
Assuming you haven't been scammed (which is unlikely!), it is not possible to brute force a passphrase that is 9-10 characters long since the permutation is just too huge (digit_length
9 + digit_length
10 = ~4e+18), your knowing 4 characters without knowing their position is not going to change anything.