Your email campaign can be brilliantly written, perfectly segmented, and beautifully designed — and still land in spam. Deliverability is the silent killer of email marketing performance.
The Authentication Stack
SPF: A DNS record that specifies which mail servers are authorized to send email on behalf of your domain.
DKIM: A cryptographic signature attached to every outgoing email, allowing receiving servers to verify the message hasn’t been tampered with.
DMARC: A policy that tells receiving servers what to do when SPF or DKIM fails — quarantine or reject.
Sender Reputation Factors
Your sender reputation is determined by engagement rates (opens, clicks), complaint rates (spam reports), bounce rates, and sending consistency. Regular list hygiene — suppressing addresses that haven’t opened in 6–12 months — is maintenance, not optional.