When creating a new mailbox you might get the -1 code error while entering the password. The -1 code means that the entered password does not meet the requirements for the password policy.
There are guidelines to follow when creating a password.
The password requirements are
1. Must be 8 or more characters.
2. Must be case-sensitive.
3. Must contain numbers.
4. Must not contain the user's first name, last name or middle name.