On 12/7/20 2:47 PM, John Levine via mailop wrote:
People do use them as part of a scoring spam filter. But no sensible person uses SPF alone to do mail filtering.
Well ... maybe I'm not a sensible person then. In the spirit of truth and kickings -- thank you Taylor Mali for "What Teachers Make"[1] -- if you ask for it, I'm obliged to give it to you. So if you send me email from an unapproved IP and you have asked me to reject unapproved emails via -all, them I'm going to reject your email flat out. After all, that's what /you/ as the domain owner / administrator /asked/ me to do.
My personal option is that being soft and not rejecting on -all is nothing short of coddling people that seemingly don't know how to administer their email infrastructure.
Uh, no. I have lots of users with role accounts who read their mail at gmail. Forwarding is as useful as it ever was, even though it is ever harder to to do successfully.
Forwarding may be useful, but is it proper?Consider the policy standpoint of from the sender's point of view. I, as a domain owner / administrator / operator, provided you information on the servers that *I* authorize to send email claiming to be from my domain -and- asked you to /reject/ anything that is not from the server(s) that /I/ authorized to send email on my behalf.
To me, that very simple /policy/ (who's allowed to send and what to do with the riffraff) does indeed conflict with forwarding. But here's the kicker, /forwarding/ in general /conflicts/ with my /published/ desire. So, I'm /happy/ that SPF -- when implemented properly by receivers -- supports my stated / published goal.
The fact that SPF can't handle forwarded mail is a failure of SPF, not a bug in forwarding.
Obviously I disagree. Thankfully SPF w/ -all allows second order receivers to know that I have not authorized the first order receiver to re-send email on behalf of my domain name.
I can't prevent people from forwarding emails from my domain. But I sure can make it more difficult for them to do so.
[1] http://www.taylormali.com/poems-online/what-teachers-make/ -- Grant. . . . unix || die
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