message-mode
(invoice
 "From: \"Rudolf Adamkovič\" <rudolf@adamkovic.org>" n
 "To: Mike Mee <admin@eggheadgames.com>" n
 "Subject: Invoice " (number-to-string (my-org-invoice-number 'last)) n
 "--text follows this line--" n
 "Please see the attached invoice." q n n
 "Thank you!" n n
 "Rudy" n n
 "<#part type=\"application/pdf\" filename=\"~/org/invoice-"
 (number-to-string (my-org-invoice-number 'last))
 ".pdf\" disposition=attachment><#/part>" n
 "--" n
 (progn
   (save-excursion (notmuch-fcc-header-setup))
   (fortune-to-signature)
   mail-signature))