Hello and Thank you for the complement
You're indeed a good marketing guy! Could sell a ship in a desert.
And lo! I thought you were offering me a MailEnable solution!
I already have a separate linux server so what you suggested is one of the first possible options. Your opinion has seconded my thoughts so maybe I'll go for this. Point their mail server to a Linux Box.
BUT, they have control to their domain. In Cpanel, if an account is created they might be able to use it for hosting as well, because we cannot restrict an account to only mail in Linux. The username/password for FTP will the same as that of cpanel. I HAVE to give them access to CPANEL in order to allow them to manage Email IDs.
Hence all this confusion!
Regds
IJ