On 2020-11-24 17:22, Chris Green wrote: > > > I'm on a couple of mailing lists that have recently moved from > > > Yahoo Groups to groups.io. For DMARC (so they claim) groups.io > > > change the senders E-mail address as follows:- > > > > > > Sender Name <sender.n...@btinternet.com> > > > > > > becomes:- > > > > > > "Sender Name via groups.io" <sender.name=btinternet....@groups.io>
> It only happens to users from some domains. I have seen it only with > btinternet.com and ntlworld.com. Like you I can send replies off-list > to senders from other domains such as gmail and my own isbd.net. > > There is a faq entry about it on the groups.io web site, that's where > I found it has something to do with DMARC. It is because those senders subscribed with an address covered by a strict DMARC policy. If their address is not munged by the list, their messages will be bounced back to the list by almost everyone if they fail a DKIM check (and that's almost always). This is just a perfect storm of sh*t - DMARC misguided by itself (IMO) plus the ancient but misguided (also IMO) practice of lists munging or adding to message contents. There's no good automatic solution to build into a MUA for this, as far as I know. The best you can do is write a macro to extract the true sender, and feel lucky for using a MUA that allows that :-) -- Ian
