Many founders focus their email marketing effort on content and calls to action, without paying sufficient attention to whether their emails are actually reaching recipients' inboxes. Email deliverability is the discipline concerned with maximising the proportion of sent emails that land in the inbox rather than being filtered into spam or blocked. Understanding the factors that affect it helps founders protect the effectiveness of their email channel.
Email deliverability refers to the ability of a sent email to reach the intended recipient's inbox. It is influenced by technical factors — including domain authentication settings such as SPF, DKIM, and DMARC, which tell receiving email servers that your emails are legitimately sent from your domain — and sender reputation factors, including list engagement rate, spam complaint rate, and whether you are sending to valid, active addresses.
Maintaining strong deliverability requires good list hygiene — regularly removing inactive and bounced addresses — consistent sending behaviour, and avoiding content patterns that trigger spam filters. Starting with a reputable email service provider and following their recommended setup steps covers most of the technical requirements. Our guide to email deliverability covers the key factors affecting inbox placement and how UK founders can protect their sender reputation.