[plug] DKIM and Microsoft

[Brad Campbell]

G'day all,

Just got caught with a gotcha.

I set up dmarc on our e-mail years ago. From memory I did a plug in the pub talk about it. Anyway we recently started getting mail from one domain junked by microsoft mail recipients.
Against "best practice" I hadn't rotated the key on this domain for years, so no config changes but the problem was recent.

Turns out public signature had a space in it. It passed every DKIM validator on the net and has worked since it was set up, but for whatever reason Microsoft inbound MX started treating it as if the key did not exist.
I must have made a blue when copying it into the zone file when I first set it up. No other MX or validator saw it as a problem.

*That* took a while to track down, so I thought I'd add it to the archive.

Regards,
Brad.