That I want to install the moment the e-mails open.
That is an extremely bad idea and thankfully not possible in any new email client.
Executing when the mail was opened was exactly how many email viruses spread a few years back.
Why would you want to do that anyway? Although I would rather not think you were trying to do anything malicious I just can't imagine any legit reason for wanting to execute a program without explicit user consent.
If your intentions really are good then zip the file and add it as an ordinary attachment.
