Dan Smith via Developers developers@lists.chirpmyradio.com writes:
No, actually it's fully in the definition to have multi-line headers:
https://www.w3.org/Protocols/rfc822/3_Lexical.html#z1
Since 1982, and almost all Received headers are that way. The mail-sorting program would be at fault if it failed to properly coalesce the multiple lines before running any matching on the value.
Also, this is all generated by mailman, so you'd need to take it up with them :)
Technically you are right, but in practice a multi-line List-Id seems likely trouble, and the comment isn't really that useful as people sort on the token. Changing description to "chirp development" wouldn't lose anything and would avoid trouble, even if the people having trouble are wrong.
And, if you are going to be strict about RFCs, the From: field must contain the sender, and not be forged to be the list. See myp private reply about not modifying subject and body -- with that change, DKIM works and there is no need for kludges to avoid DMARC trouble.
73 de n1dam