Physician, heal thyself: Even I can get auth wrong!

Here is a fresh slice of humble pie: even after years of advising senders on authentication protocols and email best practices, I managed to break my own newsletter's SPF record last week.I try to practice what I preach. My newsletter list is 100% double opt-in, no spam here, and I’ve got just about every auth protocol covered – SPF, DKIM, DMARC and BIM. All in place, all passing, all correct. But then, I updated the DNS for my domain a couple of weeks ago. I did so quickly and with confidence. It’s not the first time I’ve had to transition DNS from one provider to another. Well, it turns out that routine confidence is a great way to miss something. I neglected to verify every detail of the updated SPF record, forgetting an IP address, an important one, the sending IP of my own mail server, the MTA I use to send the Spam Resource newsletter. So, when I sent my next newsletter dispatch: SPF failed across the board, without me realizing it.The deliverability impact? Not huge, but not…