WC Portal Mail component password security

Hello,

WC Portal uses WLS credential store by associating an mail server with an external application to save and manage  user's email credentials. Customer is very concerned about storing of user's email credentials in the WLS credential store. They use the same Active Directory password for all enterprise systems and they are concerned to replicate this password and make it potentially available to the WCP system administrator (what is external company) Do we have any reasonable answer to these concerns?

Regards

Pavol