The one thing missing from my posting by email setup was support for images. The Mailsave module has finally been updated for Drupal 6, and so I can now submit attachments with email posts. The one shortcoming is that files are simply added to posts as normal attachments, and so images aren't automatically displayed. I therefore have to manually insert images in the body of the post, but I actually prefer this since it's a simpler system and gives me more control.
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