On a semi-related note, using "-- -" should NEVER be used if doing
single message incremental adds. I have noticed that some users
do this. For example:
| mhonarc -add -outdir /some/path/to/archive -- -
When they should use:
| mhonarc -add -outdir /some/path/to/archive
The problem is that "-- -" causes stdin to be treated as a mailbox.
The danger is if the first line does not match MSGSEP, then the entire
message will be discarded since MHonArc looks for the first MSGSEP
before processing the mailbox. Also, unnecessary processing is done
since MHonArc is checking for MSGSEP.
The purpose of "-- -" was to make MHonArc more friendly to mailbox
pre-processors so MHonArc can be used with pipes. For example:
my-preprocessor inbox | mhonarc -- -
Note, when in single message add mode, MHonArc will ignore bogus lines
in the message header (lines that do not conform to RFC 822 syntax).
So if the MSGSEP line does appear at the start of the message (which
is common), MHonArc will silently ignore it.