First of, that is a big no, no on saving password’s. That means anyone who gains access to the account can get automatic access to the email for free and do whatever they want. You really need to re-think this option.
Ok, to your problem, one way is to re-create another Outlook profile on the customers system. When it tries to connect to the exchange server, it will ask for a password and you can do what you need there.
But, still, you are breaking a big security rule and are a hackers wet dream. Change the policy…
I dont totally agree: we use OWA for access from home / client locations for email without VPNs and do not have a security breach
If you change your password “at work” and it breaks your email, I’ve found that plugging, say your laptop, into the domain at work and logging in forces the AD / Exchange system to upgrade the credentials to your Outlook profile
And saving passwords is not all bad – Yes, anyone that somehow gets on the system is allowed in. BUT, in the case of a laptop / tablet PC, PHYSICAL security and protecting your System / AD Log-in information is more paramount than a saved email password..