[Colin F]

There is a codeblock that has to be in the subject title of your email. This (should be) is in your notification email. Unless that doesn't get updated right...

It's in the format of: [post-3-test], that being: [1-2-3]
1: "post" or "thread", indicating if this is a reply to a specific post or to the thread itself
2: the post- or threadid. whatever you indicated in 1
3: your email password.

The rest of the subject line (the code is parsed out) will be the subject of your post.
The whole message will be the content of your post. bbcode, [img] and smilies work.

There's another option on 1, "newthread", and 2 being the forumid. But this isn't tested much...