re install, how to do it
 

For reasons that I can't fully explain, I am going to have to remove sendmail and port to either exim or postfix.

My question is if I uninstall sendmail and manually install exim or postfix, can I just reinstall ispmanager? Will it just modify itself with the new email? Will it remove all of my websites and parameters?

If so can I start from scratch and the restore the information from an ispmanager backup?

Any suggestions would be much appreciated.

You do not reinstall all system, you can remove sendmail from Feature menu in the ISPmanager and install other MTA from it.

Will it remove all the email boxes?
 

Just checking.

If you delete or change email system - it delete confuration files and email data will be lost.

Well I think he can still rely on his E-mail web services.