How to :set spell in Vim only for emails?

Google is not being very helpful here. I'd like to compose emails with :set spell on, but for all other files, :set spell should be off. I am using mutt, and Vim as the editor for composing emails.

In fact, I'm curious, how does Vim know that it's an email I'm composing? Is there a command-line parameter of the type of file being edited? How does mutt know what to pass in?

Thanks.

From stackoverflow

• Try this in your .muttrc:

  set editor = "/usr/bin/vim -c':set spell'"
  

  You can find the correct path to vim with "which vim".

  MTsoul : Perfect thanks. It doesn't seem like mutt requires the full path to vim, which is great if I want to use the same muttrc file across platforms.

• Shouldn't you be using a mutt configuration command? See the following links:

  • Text Editing: http://mutt.blackfish.org.uk/editing/

• You can use an autocmd in your ~/.vimrc that gets triggered by the detected file type:

  autocmd FileType mail set spell
  

  MTsoul : How does Vim know that it's an email I am composing?

  sth : Vim knows mutts naming scheme for temporary files. If a file fits that pattern, vim treats it as a mail. (For details look into your filetype.vim that is probably located somewhere in /usr/share/vim)