Email Heading Optimisation

Definition

Email heading optimisation is the systematic process of improving the subject line and any H1, H2 or H3 headings within the email body to maximise open rates, scannability and engagement. Headings carry disproportionate weight in email performance because they are often the only content subscribers read before deciding to engage or delete.

Optimisation applies principles from direct response copywriting, readability research and behavioural psychology — testing variations in length, specificity, emotional tone, personalisation and information density to identify what drives the strongest response.

What to Test in Headings

• Subject line length: Short and punchy versus descriptive and specific
• Curiosity versus clarity: Open loops that compel opening versus explicit promises of value
• Personalisation: Including the subscriber's name, location or past behaviour
• Emotional framing: Positive versus negative, urgent versus calm, aspirational versus practical
• Information density: How many distinct points to communicate in a single heading

Best Practices

• Write headings that communicate the email's full narrative even if the subscriber reads nothing else
• Test heading hierarchy within the email body — does the subscriber journey make sense if only headings are read?
• A/B test subject lines on a subset before full deployment to validate heading hypotheses
• Review heading performance by segment — what works for new subscribers may not work for long-term customers