On Fri, May 16, 2025 at 04:04:35PM -0400, Rich Kulawiec wrote:
We referred to them as "mboxes" back in the day; the term was so
common that some programs used "mbox" as a default filename. (Can't
recall offhand, but maybe the early BSD version of the "mail" command,
AKA "ucbmail"?)
I think the filename came first, and later the file format was named
after that. I think "mbox" was the default name for a file in the
user's home directory. When the user fired up a mail reader, it moved
new messages from the system file where the MTA put them, say
/var/mail/freduser, to ~freduser/mbox. And I do seem to think that came
from BSD.
But since some standard is (usually) better than no standard, and it looks
to me like RFC 4155 was well-researched, it's probably worth using as a
reference.
Nope, sorry. RFC 4155 has a problem. Its default format, the only one
it defines, defines the From_ line rigidly, forbids ">From " escaping,
and does not use a length. It says messages should be found by
recognizing the whole From_ line, with exact syntax.
That fails when the message body includes such a From_ line, as it
might when people use email to discuss mbox format, as here. Like this:
From nobody@nowhere.invalid Thu Jan 1 00:00:00 1970
An RFC 4155 reader would take that line above as the beginning of a new
message, and would fail to read the rest of this message.
Far as I know, that RFC 4155 format has never been implemented. I think
it's best to keep it that way. I say, continue to ignore that RFC.
