DKIM, SPF, DMARC — the enterprise deliverability baseline

Mailbox providers don't score your content first. They score your cryptography. Here's the baseline every serious sender needs — and how much of it should be automated.

What each record actually proves

• SPF — the sending server is authorized by the domain owner. One DNS TXT record, but brittle: more than ten lookups fails.
• DKIM — the message wasn't modified in transit, signed with a private key only you hold. Rotate the key; providers keep verifying during propagation.
• DMARC — ties SPF and DKIM to your visible From: domain, and tells providers what to do when both fail: none, quarantine, or reject.

Together they answer the only question that matters at the gateway: is this really from who it claims to be from?

The baseline most teams miss

Google and Yahoo's 2024 sender requirements made authentication table stakes for bulk senders — but enterprise bar is higher: per-domain DKIM keys (not shared), alignment between d= and From:, DMARC at enforcement, and TLS on every hop.

What SendFlit automates

1. add domain          → we generate per-domain DKIM keys
2. publish 3 records   → SPF include, CNAME verification, DMARC
3. verified            → every send signed, aligned, logged

Bounce suppression, RFC 8058 one-click unsubscribe, and paced daily limits are on by default. The parts that are pure operational discipline shouldn't be your team's job to remember.

Review-proof by default

When security asks "prove the mailstream is authenticated," the answer should be a log line, not a project. In SendFlit every message carries its authentication result — searchable, exportable to your SIEM, attributable to the key that sent it.