I find Mail to very lacking when it comes to editing characteristics. I have tried several times in the past to use it. Then I figured it was more like BETA software, now years later its still like Beta software so it must be as mature as it is going to get.
The message filter idea has been in other editors for years. Nothing new there.
Try drag and drop, which Apple has been promoting for years. Mail is crippled for that feature. Try bullets... gone. Try indented paragraphs...gone.
I like to insert pictures with the text. Try dragging and dropping a picture into Mail..... gone. Attaching a picture gets confusing. Attaching inserts a picture into the text sometimes, well most of the time. But not always. So how do you attach a file or picture you don't want in the text?
Obviously I use these features daily so I have stopped trying to use Mail again.
My Claris Emailer had personal favorite user interface. Eudora has email filter, OSX address book access (but not correction!!!) and does all the other things. User interface can be lived with but its no Claris Emailer.
Bottom line, Mail looks like a digital shop class project.
Jim
Setting Up Mail for Mac