On Thu, Jun 18, 2020 at 08:02:11AM +1200, Richard Hector wrote: > > See <https://jdebp.eu/FGA/mail-mbox-formats.html> for more details.
> I understand the phenomenon. I don't understand why modern software (eg > the list software) still does it. Well, imagine you're a mailing list. A dozen people are subscribing to you, and you have no way to know which MTA and mailbox formats each of your subscribers is using. If you don't do the From mangling, and you send a message to subscriber #7 who happens to be using a traditional /var/spool/mail mbox format, the results could be undesirable -- #7 will see half a message followed by a broken message. The easy fix is to perform From mangling on every message that passes through you. That way, people won't see massively broken messages. Occasionally, people will see a single broken line in a message, but 99% of the rest of your traffic will be OK. It's a conservative strategy, and it works... mostly. Close enough.
