On May 14, 2014, at 11:47 PM, Stephen J. Turnbull <step...@xemacs.org> wrote:
> Peter Shute writes: > >> When MS365 forwards the mails sent to the distribution list, should >> that make the DMARC authentication fail? I thought that only >> happened if you made changes like adding a prefix to the subject >> line like Mailman does. > > If it forwards verbatim *and* the sending domain signs the mail with > DKIM (the common case), DMARC validation will succeed. Without DKIM, > DMARC validation is guaranteed to fail. However, even in the sender > uses DKIM, *any* change *whatsoever* to the body will cause validation > to fail, and there are several changes to the header that could cause > it to fail. Furthermore, which parts of the header are protected by > the DKIM signature are determined by the sender, not by DMARC AFAIK. > > If distribution lists are pure forwards, MS365 will be OK. But I find > it hard to believe that that level of functionality is popular with > users -- there's a reason why all popular MLMs implement subject > prefixes, body headers and body footers, and it isn't "because it's > the Microsoft way". > > Especially as legally mailing lists are required to add unsubscribe instructions in the footer. best regards, Larry -- Larry Finch finc...@portadmiral.org ------------------------------------------------------ Mailman-Users mailing list Mailman-Users@python.org https://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Security Policy: http://wiki.list.org/x/QIA9 Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: https://mail.python.org/mailman/options/mailman-users/archive%40jab.org
