Very needed and fine plug-in concept! End-user and admin simple is perfect.
Have "every time" problem with an e-mail's body text making it into a post with an image attachment. When NO e-mail image attachment, then body text is posted, but with an image attachment (and whether or not a
[gallery] shortcode is included in the body), then the e-mail message text (plain text or HTML message text) does not make it into the post.
Have tried these e-mails in various combinations on different servers with your 1.0.4.b plug-in and WP 3.6.1 and 3.7.1, but the result is always no body text posts with an attachment, but the body text always posts when the e-mail does not have an attachment.
When there is an image attachment, then the image is always entered into the Media Library and associated with the post, just fine and dandy. - No PHP errors/warnings in the logs ever.