This is not Yahoo's fault. Now it's time to read and understand SPF, DKIM and DMARC. All three of them have been implemented at e-mail server level in order to allow a domain owner to issue a set of policies. These policies mandate e-mail receiving systems to flag or discard fraudulent messages. (e.g. e-mails bearing senders e-mail address from @bank.com but crap messages sent by servers which have no relationship with bank.com.)
SPF lists the IP addresses of the servers authorised to send e-mail from bank.com. DKIM authenticates and digitally signs e-mails from bank.com DMARC uses both SPF and DKIM ; if a mail message fails both checks, then the message fails DMARC. Mailing list software such as Yahoo Groups alter the message (inclusion of a [tag] in the subject; addition of a footer) so the DKIM signature becomes invalid as the message is tampered with. SPF fails also because the message from [email protected] is not spit out by their original server, but resent from a Yahoo server. The unique solution, which has been adopted by Yahoo, is to rewrite the sender address, discard the original sender, and set [email protected] as the sender. The original sender may or may not be shown in the text part describing the sender address. Frédéric On Tuesday, March 5, 2019 at 2:58:31 PM UTC+1, Greg Troxel wrote: > Also, the problem is likely that yahoo is rewriting the sender's > address, and putting something else in the From: field. You could try > asking them to stop :-) More likely to be successful would be to ask the > group to move to a mail provider that doesn't do this... > > > -- You received this message because you are subscribed to the Google Groups "K-9 Mail" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
