What Is SPF and How to Set It Up for Cold Email Sending Domains

SPF — Sender Policy Framework — is a DNS TXT record that tells receiving mail servers which IP addresses and services are authorized to send email on behalf of your domain. When a receiving server gets an email claiming to be from your domain, it checks the SPF record. If the sending IP is not listed, the email fails SPF authentication and is more likely to be treated as spam or rejected outright.

Why SPF Is Non-Negotiable for Cold Email

Modern email systems including Gmail, Outlook, and Yahoo use SPF as a baseline authentication check. An email sent from a cold email sending platform like Saleshandy or Instantly that fails SPF authentication will consistently underperform on inbox placement — regardless of how good the copy is. Setting SPF correctly is the first step in any cold email infrastructure setup.

What an SPF Record Looks Like

An SPF record is a TXT record in your domain's DNS settings. A basic one for Google Workspace looks like: v=spf1 include:_spf.google.com ~all. The include: directive specifies which mail systems are authorized. The ~all at the end is a soft fail — emails from unauthorized sources are marked as suspicious but not hard-rejected. For cold email sending platforms, you add the platform's SPF include directive alongside your mail provider's.

How to Set Up SPF for a Cold Email Sending Domain

For dedicated cold email sending domains (separate from your main domain), the SPF record needs to authorize only the cold email platform. If you're using Saleshandy or Instantly, their documentation provides the exact include string to add. Log into your domain registrar's DNS management panel, add a TXT record at the root (@), and paste the SPF string. Changes typically propagate within 30 to 60 minutes and can be verified with MXToolbox's SPF record checker.

SPF Alone Is Not Enough

SPF authenticates the sending server but not the email content or header structure. It must be combined with DKIM and DMARC to provide full authentication coverage. The full three-record setup — SPF, DKIM, and DMARC — is what Omni configures on every sending domain as part of the done-for-you outbound system.