diff --git a/.vimrc b/.vimrc
--- a/.vimrc
+++ b/.vimrc
@@ -446,7 +446,7 @@ let g:interestingWordsRandomiseColors = 
 " {{{ Commands
 " Preview markdown mail -- I edit with headers so I box them in a code block.
 command! MailPreview     enew | set bt=nofile | 0r # | exe 'norm 0O```<Esc>}O```' | silent exe '%!mutt-md2html | mutt-html2txt' | 0
-command! MailPreviewHTML enew | set bt=nofile | 0r # | exe 'norm 0O```<Esc>}O```' | silent exe '%!mutt-md2html' | 0
+command! MailPreviewHTML enew | set bt=nofile | setf html | 0r # | exe 'norm 0O```<Esc>}O```' | silent exe '%!mutt-md2html' | 0
 
 " Diff unsaved buffer
 command! DiffOrig vert new | set bt=nofile | r ++edit # | 0d_ | diffthis