So with all of this email fun, it has been good to get some validation that it has had an effect. I signed up for Microsoft's SNDS (
link here), which is a free service that lets mailers see how their mail is being treated by Microsoft (at hotmail.com, outlook.com, and a few others). Once I signed up, I saw that our mail here was classified as red, 45 days in a row. Sadly, they only keep 45 days of history, so that's all of them. Here's the scale they use:
After the improvements I made this week on rDNS, SPF, DKIM, DMARC, and setting up FBL's at Microsoft, Yahoo, AOL, and perhaps some more I've forgotten; here's what I saw when I logged in this morning: