[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Nmh-workers] 78 column limit
From: |
Ken Hornstein |
Subject: |
Re: [Nmh-workers] 78 column limit |
Date: |
Tue, 04 Dec 2012 14:40:56 -0500 |
>So... do I conform to standards or make my my recipients unhappy? In passing
>I note that almost all the Email I get, not from address@hidden, has
>very long lines.
Let's look at the standard. Specifically, the latest update to RFC 822,
RFC 5322. It says:
2.1.1. Line Length Limits
There are two limits that this specification places on the number of
characters in a line. Each line of characters MUST be no more than
998 characters, and SHOULD be no more than 78 characters, excluding
the CRLF.
So as long as you're keeping it under 998, you're keeping it within the
hard limits of RFC 5322 (that limit really applies to SMTP). Note that nmh
will happily send a message with >998 characters per line; whatever is in
the draft file just gets blasted to the SMTP server. That's a violation
of the next paragraph of RFC 5322:
The 998 character limit is due to limitations in many implementations
that send, receive, or store IMF messages which simply cannot handle
more than 998 characters on a line. Receiving implementations would
do well to handle an arbitrarily large number of characters in a line
for robustness sake. However, there are so many implementations that
(in compliance with the transport requirements of [RFC5321]) do not
accept messages containing more than 1000 characters including the CR
and LF per line, it is important for implementations not to create
such messages.
But I was (rather cheekily, I admit) talking about the next paragraph in
particular:
The more conservative 78 character recommendation is to accommodate
the many implementations of user interfaces that display these
messages which may truncate, or disastrously wrap, the display of
more than 78 characters per line, in spite of the fact that such
implementations are non-conformant to the intent of this
specification (and that of [RFC5321] if they actually cause
information to be lost). Again, even though this limitation is put
on messages, it is incumbent upon implementations that display
messages to handle an arbitrarily large number of characters in a
line (certainly at least up to the 998 character limit) for the sake
of robustness.
We can display stuff with lines >78; they just line wrap poorly. Fixing
this is ... well, hard. Take a look at mhl and you'll see what I mean.
I generally restrict my email to 78 columns or less, and I've never heard
from anyone that my emails look "jagged". Maybe it looks jagged to everyone
and they're not saying anything; hard to tell.
But I have a question for you; does the emal you get that has really long
lines come in as text/plain with a 7bit encoding? Or does it come in
as quoted-printable? In my limited experience the former is rare; the latter
is common. The reason I noticed is that replyfilter assumes that text/plain
with a 7bit (or 8bit) encoding is exactly how the sender wanted it to be
displayed and thus it will not run the message through "par" for formatting.
I did this because I was replying to a lot of messages with code in them
and par really chewed that text up. In my experience people with long lines
generally used q-p or base64 or some other encoding.
So, what to do? We'll, I'm not sure; with the current tools you're
going to make someone unhappy. We don't right now have a good way
to compose things like format=flowed, and it's not clear to me how
that would work without some editor smarts. I'm open to suggestions
(code would be better).
--Ken
- [Nmh-workers] UTF=8 in message bodies, norm, 2012/12/04
- Re: [Nmh-workers] UTF=8 in message bodies, Ken Hornstein, 2012/12/04
- Re: [Nmh-workers] UTF=8 in message bodies, Ralph Corderoy, 2012/12/04
- [Nmh-workers] 78 column limit, norm, 2012/12/04
- Re: [Nmh-workers] 78 column limit, Jon Steinhart, 2012/12/04
- Re: [Nmh-workers] 78 column limit, norm, 2012/12/04
- Re: [Nmh-workers] 78 column limit,
Ken Hornstein <=
- Re: [Nmh-workers] 78 column limit, norm, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Ken Hornstein, 2012/12/05
- Re: [Nmh-workers] 78 column limit, norm, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Ken Hornstein, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Ralph Corderoy, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Ken Hornstein, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Michael Richardson, 2012/12/06
- Re: [Nmh-workers] 78 column limit, norm, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Earl Hood, 2012/12/05
- Re: [Nmh-workers] 78 column limit, Ralph Corderoy, 2012/12/05