Many of the emails I receive demand a lot of effort from me before I work out what I am being told or being asked to do. I’m reasonably confident that this is not because I’m stupid.
If the recipient of your email has to engage in struggle before starting on any actual task, chances are that the task is going to suffer. Put the effort in up front. At your end.
Get to the point quickly and make sure the point is the one you wanted to make.
I won’t go on. Instead, here’s a perfect Dilbert cartoon that highlights the issue.