SPF Failure / Gmail couldn't verify that scryptmail.com actually sent this message

I noticed the following warning in my Gmail when SCRYPTmail started delivering again today:




The source of the problem is that SCRYPTmail is sending from IP's not listed in the SPF record.

In this case, it delivered over IPv6 to Gmail.

Received-SPF: softfail (google.com: domain of transitioning popowich@scryptmail.com does not designate 2607:5300:61:e06:: as permitted sender) client-ip=2607:5300:61:e06::;
Authentication-Results: mx.google.com;
spf=softfail (google.com: domain of transitioning popowich@scryptmail.com does not designate 2607:5300:61:e06:: as permitted sender) smtp.mailfrom=popowich@scryptmail.com

When you get a moment, don't forget to add an ipv6 part to the SPF record.