unrmail-mbox-format

unrmail-mbox-format is a variable defined in `unrmail.el'.
Its value is

mboxrd

Documentation:
The mbox format that `unrmail' should produce.
These formats separate messages using lines that start with "From ".
Therefore any lines in the message bodies that start with "From "
must be quoted. The `mboxo' format just prepends a ">" to such lines.
This is not reversible, because given a line starting with ">From " in
an mboxo file, it is not possible to know whether the original had a ">"
or not. The `mboxrd' format avoids this by also quoting ">From " as
">>From ", and so on. For this reason, mboxrd is recommended.

See also `rmail-mbox-format'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.