mutt send mail from command line, with headers inside text file

Can mutt send mail from command line without command line parameters, with subject, cc, bcc, reply-to, in-reply-to all defined inside mail.txt file with body of the message too (the same file format like mutt opens to me when i press m-send mail, or r-reply to mail). ... So that I can: - press 'r' on received mail, prepare my reply message, save it with ':w ~/preparedmail.txt' in vim ... cancel sending - and than run $ at 8:00 <<< "mutt < ~/preparedmail.txt" ... or is there other tool that will accept this file format. Or other way to achieve this.