Subject wrap with tab character

[Swen-haubold]

Mailman: 2.1.2

The subject line is wrapped by a tab character, if the line
contains more than 78 characters. In this case a space is
replaced by an tab character.

This behaviour gives trouble with some e-mail client and
is also not handled by MHonArc correctly.

In an e-mail client a long space is shown or a special
character. MHonArc simply removes the tab character
therefore two words are combined, e.g. the tab is
inserted between the two word "and" and "delivery"; in

the archive the subject contains the new word
"anddelivery"

[http://sourceforge.net/tracker/index.php?func=detail&aid=736559&group_id=103&atid=100103]

[Disser (disser)]

I notice this also with Mailman 2.1.1. I don't see code in mailman doing
it,
so it appears to be in email.Header or unicode.

[Jwilson75503 (jwilson75503)]

This behavior seems to still occur in 2.1.6

http://www.mail-archive.com/mailman-developers%
40python.org/msg09027.html

[Tokio Kikuchi (tkikuchi)]

RFC 2822 example states:

           Subject: This is a test

   can be represented as:

           Subject: This
            is a test

Therefore, if MHonArc or a MUA simply removes tab char and
not insertes a space in place of the FWS (folding white
space), it is his fault. Mailman now select FWS from tab or
space as appeared in the original message.

[Bovineone (bovineone)]

Originator: NO

Still occurs with Mailman 2.1.9 and MS Outlook 2003 as MUA.

It seems that many MUAs may implement header unfolding by removing the
CRLF and the first WSP chracter, rather than only the CRLF as the RFC
recommends.

RFC 2882 also states that the line folding limit "MUST be no more than 998
characters, and SHOULD be no more than 78 characters, excluding the CRLF."
It seems reasonable in these modern days to use longer line lengths beyond
the conservative 78 character limit and use the 998 limit instead.
Increasing the line folding limit would not really fix the original
problem, but would reduce the impact on most users.