I occasionally import Unix style files into yarn with the:
import -r filename
Unix type message headers are ordinary text that start with a from
line without a colon:
From someone@where.com may 3, 2000 +3000
followed by the usual kinds of lines such as To: Subject: Reply-to:
After the header is a single blank line.
Alas, yarn's import does not check much if a Unix header is really a
header. ANY line in a message that starts with a
>From
followed by a space, is treated by yarn as the start of a new message!
You can test this yourself by creating some real messages and including
a sentence that starts with From . The result is the kind of mess that
you would expect from such a misunderstanding.
Therefore, either be very careful when importing Unix type mail files,
or use some editing program like sed or off to make sure there are no
lines in the body of messages that start with From (for instance, indent
such lines a few spaces).