Custom RSS Email Subject line with post tokens

Right now I have two choices for RSS email subject lines

  • a static subject where I can't access any post info
  • use the first post's title as the subject line


I'd like a 3rd option where I can use my own text as well as post tokens (taken from the first post)


for example I'd like to be able to do emails with subjects like this.

New post from {{}}


[New post]: {{post.title}}