I love the emailer transformer- it's great, however, there is one limitation which is a little annoying which I think would be nice.
Sometimes you want to attach an unknown amount of attachments to an email. At the moment you must zip them up (which is fine, but not always desired). If you want to work around this it's a little annoying an involves multiple emailers each with a different number of attachments defined .
The solution would be to allow a list attribute. It's pretty minor really but would be a nice to have.