Sorry, I wasn't clear in my original question. I know what the mbox format is: blank line followed by Wrom: P
However, the formats seem to differ between Horde and Neomail - i.e. some of my files can be read in Neomail, but not in Horde (invalid format). I'd like to determine what is making them bork with Horde, because I'm moving to Horde/Thunderbird.
thanks
neil