Hello. Odd problem here. If I run Postie manually, I get the post coming in just fine. This also means debug shows everything working fine as that is manual as well. However, if I just let the script run (tried every 5 minutes and every 10 minutes just to see if that was a factor, it was not) then I get the "tmptitle - Draft" in Posts on the back end. Attachments are stripped out as well.
Running WP 3.9.1 and Postie 1.5.19. Changed themes with same effect including Twenty Fourteen and Twenty Thirteen so this appears to be regardless of theme as well. This *does* appear to be related to the presence of a plugin we use to auto-rotate iPhone images (EXIF fix) called Image Rotation Repair. Works if I disable it. However I use this same combo on multiple other sites with no problem. Just seems to affect this one. Curious if you had any insight here as I am stumped.