Actually - you are right. I checked the RFC and the file indeed has incorrectly folded lines (no leading space). The files are generated by Outlook - the world's most popular email system - so incorrect or not, I still need to parse them and using your API I cannot access the additional lines.
My other requests still applies, it should be possible to gain access to the ordered set of lines from the file which would provide a workaround, or the parser should be more tolerant of file format anomalies.