Email deliverability basics for cold outreach

Email deliverability is the single most overlooked aspect of cold outreach. You can write the perfect email to the perfect prospect, but if it lands in spam - or never arrives at all - none of that matters. Understanding deliverability basics is essential before you send your first campaign.

The foundation is DNS authentication. Three records - SPF, DKIM, and DMARC - tell email providers that you're authorized to send from your domain. Without them, your emails are far more likely to be flagged as suspicious. Setting these up correctly is non-negotiable.

Domain reputation is built over time. A brand-new domain has no reputation, which means email providers treat it with suspicion. This is why domain warming is important - gradually increasing your sending volume over two to four weeks so providers learn to trust your domain.

Sending volume and patterns matter. Sending 500 emails from a domain that sent zero yesterday is a red flag. Consistent, moderate sending volumes look natural. Sudden spikes look like spam. Most cold outreach should stay under 50 to 80 emails per day per domain.

Content affects deliverability too. Emails with excessive links, images, HTML formatting, or spam trigger words are more likely to be filtered. The best cold emails are plain text, short, and conversational - which also happens to be what gets the most replies.

Finally, monitor your results. Track bounce rates, spam complaints, and inbox placement. If your bounce rate exceeds 3 percent, your list needs cleaning. If you're getting spam complaints, your targeting or messaging is off. Deliverability is not a set-and-forget setup - it requires ongoing attention.