A great tip that I use is to write the email as I normally would (context, details, conclusions, actions) then copy and paste the conclusions or actions back to the top and reword as a “hook statement”, such as “We need to spend £25K upgrading the email server storage capacity, so I have outlined the reasons why below”

My own bad habit used to be to construct an argument from background facts, options, pros and cons, then conclusions, in order to demonstrate that I had been through the mental hoops to get there in a reasoned fashion. This linear style lacks punch, whereas putting the actions right at the top gives the PHB a better idea of why the email matters.
If the boss chooses to read on for the reasons or not, that is then his choice. I am quite happy for them to simply trust my judgement and reply “just do it”

Of course that might not be a valid assumption.

If there is a driving business reason for switching to Notes you actually may be far more productive in that environment than with Exchange. However, it sounds like a pretty big switch to make if there isn’t any business reason behind it. It is kind of like taking an existing house and deciding you want to put in a different type of foundation–you better have a very good reason to justify the expense.

For me the subject of the email was important. Ideally, if I ever need to search back through my emails, I want the subject to contain my search words. So ask yourself, if your boss has to find this email later, what words would s/he probably think to use as search words when looking for this email at a later date?

Big tip though, if your boss is a micro-manager, they want all the nitty gritty and often tear apart your e-mails, and attack you if they are too short in my experience.