Hi,
[I prefer discussion be directed to mailman-developers, so Reply-To is set. But if you're not subscribed to -developers, following up here is OK, and I'll eventually summarize to -developers. Just don't followup to both.]
I just noticed that among the agents that send non-conformant long lines[1] is HyperKitty. Nowadays violating the 80 octet limit is common and MUAs mostly handle it, but the 1000 octet limit is enforced by many MTAs[2]
I think that HyperKitty should format mail per RFC 3676 format=flowed https://tools.ietf.org/html/rfc3676#section-4. However, I don't use "modern" (aka crappy HTML-oriented) clients, so I don't know whether they handle format=flowed properly.
Discussion greatly desired.
Steve
Footnotes: [1] RFC 5321: MTAs MAY impose a limit >= 1000 octets including CRLF. RFC 5322: MUST be <= 1000 octets including CRLF, SHOULD be <= 80 octets including CRLF.
[2] In practice, most (?) MTAs just break the line at 998 octets and insert CRLF rather than reject the message. I assume they would break happily in the middle of a multi-byte character, i.e., any non-ASCII in a UTF-8 text.