Hi there I noticed that some user sends an email from a hotmail account to to a forwarding address entry on the server. The server then forwards that email to multiple recipients. This all works fine, except in gmail such emails land in the spam folder. The reason is that Microsoft's SPF doesn't allow my server to send those emails: Code: Received-SPF: softfail (google.com: domain of transitioning [email protected] does not designate 176.9.139.175 as permitted sender) client-ip=176.9.139.175; How can this be fixed? SRS seems to be a way: http://www.openspf.org/SRS / https://www.mind-it.info/2014/02/22/forward-postfix-spf-srs/ but I'm not really sure how that works together with the perfect setups for ISPC. Any input?
Tell your users, that they should not forward mails in this way. If they will do it anyway, that´s just there problem. The should just "pull" the mails. If you rewrite the mails (never tried something in your links) you can also forward spam and your ip could be blacklisted.
It's up to you if you allow external forwards, set email forwards to 0 in client limits to limit customers to email aliases on the local server.