I've added Post Format support to the Postie plugin, which allows you to specify the Post Format in the subject using a special delimiter. (It works the same way as the Custom Post Type support I added a few months ago, which has been officially rolled into the plugin.)
First, you'll need to modify
postie-functions.php and add a few additional lines as described in this gist:
Then, when you compose an email, you can add the Post Format to the beginning of the subject, followed by two colons, followed by the Post Title. For example, if I wanted to post an Aside, I could send an email with the following subject:
Aside :: My Aside Post
Things I haven't tested:
- Combining Custom Post Type with Post Format (e.g., "Movies // Aside :: My Aside Movie Post Title")
- Posting without specifying the Post Format. This should work by just leaving it out of the subject (e.g., "My Standard Post Title"), but I haven't tested it.