On 17 Jun 2020, at 4:23, Alessandro Vesely wrote:
There are a few shortcomings of From: rewriting, which could be mitigated adopting suitable conventions. For example, MUAs' replying to author, or storing rewritten addresses in address books.
As soon as you start down that path, you have eliminated one of the purported values of From: alignment: MUAs will start using those conventions (X-Original-From:, decoding encoded Froms) and display that information to the user instead of what's in the From: field, in which case you're going to need X-Original-From: alignment, and down the spiral we go. (For those who are amused by such things, do a web search for "X-X-Sender".) I am not convinced by many of the arguments for From: alignment, and think the problems lie with the lack of semantics able to be conveyed by a DMARC record in these cases, but I seem to be in the rough on these points. But there is no magic bullet in "suitable conventions".
Now, if we make a semantic effort, we must recognize that the address of From: as a matter of fact refers to the "managing editor" of the corresponding mail flow, whereas the display name may indicate the actual author.
No, the semantics of From: have not changed generally. It's that some mailing lists have to change the semantics of From: in the face of the inability of DMARC to express the semantics that they want. I can get together with a group of my friends and decide that the word "sunny" really means "cloudy", but unless the whole English-speaking world is on board with me, communication is bound to have problems.
To say nothing of the Sender: field, which wasn't designed for that role anyway.
Sender: has had pretty much the same definition back to RFC 733. It was perfectly designed for "the thing that sent the message, independent of the author."
That's how email has evolved after introducing authentication.
For most email, the meanings haven't changed at all. For a certain class of mail, authentication of a certain sort has forced arbitrary changes that have made the semantics ambiguous as compared to the past.
I'd hope rfc5322bis will recognize those changes.
I sure hope not.
Meanwhile, if we gather consensus on how to do it better, it'd be fair to write it down, no?
Assuming you can gather consensus. I'm not convinced you can. pr -- Pete Resnick https://www.episteme.net/ All connections to the world are tenuous at best _______________________________________________ dmarc mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmarc
