John Levine wrote:
I'm honestly trying to figure out whether any mail systems treat mail
from sub.foo.com as being from foo.com when they make decisions about
sorting, filtering, and so forth. That's why I'd really appreciate
some
actual examples if there are any. I'm not trying to be
confrontational
here, I'm trying to gather data.
I can think up examples where sub.foo.com would inherit foo.com's BAD
reputation. That's easy; we've all seen spammers set up a domain and
rotate through subdomains, and we've seen not-quite-entirely-evil
senders do similar things.
I can't come up with very many examples where the subdomain should
inherit the parent's GOOD reputation. Most banks, hopefully, though
I've seen counter-examples there too: a branch office might have
crappier mailing practices than the main corporate office.
Even the inheritance of badness isn't isn't a safe generalization:
yahoo.com (which has real freemail users) will have a worse reputation
than upcoming.yahoo.com (which I believe consists solely of
announcements sent to registered users.) Nearly all ISPs will be in the
same situation.
_______________________________________________
NOTE WELL: This list operates according to
http://mipassoc.org/dkim/ietf-list-rules.html