set formatprg=fmt\ -w78
GNU fmt uses the line-breaking algorithm from TeX.
This works much, much better than vim’s built in formatter, and will make your emails look pretty; if like me you edit your emails in vim from mutt.
I can’t imagine using some lousy generic text box to edit email messages – although I am putting up with it for this blog! I should switch back to blosxom, or spend a few minutes hacking up my own RSS export gadget.
I could write emails without line-breaks, one line per paragraph, but then my emails will appear ridiculously wide in your average brain-dead mail reader. I’m looking at you, Outlook – do I want to read foot-and-a-half-wide columns of text? There’s a reason why newspapers keep their columns narrow – it’s easier to read!
if you like fmt, you’ll probably love par. I’ ve been using it from within vi to reformat email (and code, esp. comments) since the mid 90s.
Package: par
Version: 1.52-3
Description-en: Paragraph reformatter
Greatly enhanced fmt type program by Adam M. Costello.
Can be used within vi or other editor to automatically reformat text
in a variety of ways.
Perfect for use with email & usenet messages as it correctly handles
multiple levels of quoting characters.
This version includes a patch allowing multi-byte and multi-width character
encodings.
Homepage: http://www.nicemice.net/par/