Your email is delivered to a unix server. This also requires a username and password. Financial Management Department applications run off the CF11 NT server. The staff database is maintained on a unix server in Sybase. If you use this database, the Sybase account is separate from your unix email account.
Life is simpler, if less secure, if all of the usernames and passwords are the same.
Passwords can be the same on all systems, but should meet the security requirments of each system. Your email password needs to be unbreakable because the email system can be accessed from anywhere in the world. If your password is crackable, your account will be disabled. The theory is that if we can crack your password, intruders may also be able to do so. Suggestions for a method to generate a strong password are in the Unix password help.