Ok, second problem first. The box is only something you see. It just designates an area of text that's either rich text or html formatted. If you convert to plain text it'll go away, but that shouldn't be necessary.
First problem, when sending an email with a graphic attachment, make not of the lower right corner of the window. You should see an Image Size menu. Yours sounds like it's set to Small, Medium or Large. Try setting it to Actual Size and your image files shouldn't shrink down when sending.
I'm having a problem with Mail on OS 10.6.4.
When I send a photo that comes from my computer, Mail shrinks the display size to pretty tiny, regardless of the file size. It didn't used to do this.
When the photo has been emailed to me, regardless of how I move it over, it does far worse: it shrinks the file size from as much as 6.6 MB to a bit less than 40 KB. THe only solution that sometimes works is to import it to a graphics program, re-save it, and then send it? a major pain.
I've tried dragging & dropping from incoming to outgoing email, to desktop (preserves size) and then to email (where it shrinks), using the Save command in the email, using contextual menu. I've used the attach comand, dragged and dropped, and used GraphicConverter's Email/ Full Size command, and used iPhoto's Share/Email/Full Size command.
Second gripe: when I forward an email or copy and send it repeatedly, a box appears around the message. How do I get rid of it?
Or, at this point, I feel I should be asking for recommendations for other email software.
MacBook Pro early 2007