May I add my experience with tis issue.
I am running 3.4.2, with the latest version of Postie, which I updated today. I have been running an older version and successfully receiving text emails with attachments, which posted automatically to Postie, without issue. The last one I had was about 3 weeks ago.
In the last 6 weeks or so, I have not updated any plugins or anything else technically. Posts worked automatically and successfully.
However, in the last 3 weeks, the automation stopped (even though the blog was being visited), and worse: any posts with images were posted (pending) with only the title and the images-- the text was totally stripped. However, pure text posts, without images were posted intact.
But none were automated. I wondered why I had no posts from my collaborator who is posting from mid-Pacific; today when I did a manual check, there were 13 posts, from the last 4 weeks.
Something has changed... hmmm!
Moreover... 2 test posts, sent today from London & the Galapagos, to the Postie address did not even arrive... my next step is to check with my host if they can track anything.