On Tue, Jul 25, 2017 at 08:33:16AM -0700, geneb via cctalk wrote: [...] > For example, if you sent classiccmp.org an email with your "from" header > tweaked to be from [email protected], the mail server will reject it > because your mail server isn't an authorized sender for the deltasoft.com > domain. If it doesn't, someone needs to give Jay a stern talkin' to. ;)
It'd be wonderful if SMTP mail worked like that, but sadly it doesn't. In this case, deltasoft.com doesn't even have a SPF record, so the de facto default policy applies where any mail client can send mail from that domain. SPF is no magic bullet either, because it's often misconfigured, and a hard rejection on SPF failure is likely to bin a lot of legitimate mail.
