The password we use to access the PFX files is entered under Settings>SSL Certificates when logged in as a system administrator, and that password should match the one you have set up in your deployment script where it exports the newly renewed certificate to PFX format. If you can find the password for that script/export configuration and copy it over to SmarterMail that should get you back into those certificates. 

Thanks for that. I am logged in right now as the admin. I edit the Certificate Password (tried pasting it and typing it) and the Save button is never enabled.

I can BTW edit other items in General, Protocols and such and the Save button enables in those cases. Cancel button enables as I enter the password.