> On 10-Sep-2015, at 3:22 AM, Bron Gondwana <br...@fastmail.fm> wrote: > > We have SPF records. The problem is that our customers can set up > sieve rules to forward any mail at all, so we can't guarantee that SPF > will always pass.
If you aren’t treating forwarded mail like it has leprosy, you really ought to. Segregating it onto its own IP which is clearly named - like forwarder.fastmail.fm - would be a very good idea. Else, the blocking you face will most likely be because of huge amounts of spam that slips past your inbound filters and leaks out of your outbounds due to the forwarding. DKIM / DMARC / SPF your customers as much as you will, having your outbound traffic mixed with bot, snowshoe, nigerian and random other spam that leaks past your inbounds is essentially hanging a giant “block me!!” sign on your outbound MTAs. —srs _______________________________________________ mailop mailing list mailop@mailop.org http://chilli.nosignal.org/mailman/listinfo/mailop
