http://bgall.uk/tags/spf/ Recent content in spf on Hugo -- gohugo.io en-gb Ben Gallagher Sat, 23 Aug 2025 10:47:24 +0100 http://bgall.uk/posts/spf/ Sat, 23 Aug 2025 10:47:24 +0100 http://bgall.uk/posts/spf/ Introducing My SPF Flattener Lately I’ve been scratching a very specific itch: SPF records. These tiny TXT records live in your DNS and tell receiving mail servers who is authorised to send email on behalf of your domain. When they work, you never notice them. When they don’t, your mail gets quietly thrown into the spam abyss. It turns out there are two gotchas baked right into the SPF specification: you only get ten DNS lookups and each string is limited to 255 bytes.