Definition
A conditional block (also called a dynamic content block or conditional content) is a segment of an email that appears only when specified conditions are met. Common conditions include subscriber attributes (location, industry, plan type), behaviour (purchase history, engagement level), or external data (weather, inventory, time of day).
Conditional blocks enable one-to-one personalization within a single email template. Instead of creating separate emails for each segment, you create one email with conditional blocks that show relevant content to each subscriber and hide irrelevant content. This reduces template maintenance while increasing relevance.
Conditional Block Examples
| Condition | Content Shown | Content Hidden |
|---|---|---|
| Enterprise plan subscriber | Enterprise feature announcement | Basic plan upgrade prompt |
| Purchased last 30 days | Product care tips | Welcome discount offer |
| Located in UK | UK event invitation | US event invitation |
| Weather = rainy | Rainy day product suggestions | Outdoor activity promotions |
| Engaged (opened last 14 days) | Latest blog post | Re-engagement message |
Best Practices
- Use conditional blocks to personalise without creating multiple templates
- Keep conditional logic simple — complex conditions are hard to maintain and test
- Always provide a default fallback for every conditional block
- Test every possible condition outcome before sending
- Document your conditional blocks so team members understand the logic
- Monitor performance of each content variation to refine personalization
Related Glossary Terms
AMP Dynamic Content in Email
AMP for Email enables dynamic, interactive content within email messages, including live product feeds, real-time pricing, countdown timers, and embedded form submissions without leaving the inbox.
Content Personalization
Content personalization dynamically tailors email content to individual subscribers based on their behaviour, preferences, demographics, and past interactions with your brand.
Countdown Timers in Email
Countdown timers in email for urgency: dynamic real-time rendering via GIF or embedded API, implementation approaches (GIF, CSS, AMP), timezone considerations, fallback strategies, and typical conversion lift of 10-30%.
Personalization at Scale
Personalization at scale uses data, automation, and AI to deliver individually tailored email content to large subscriber lists — treating each subscriber as a segment of one without requiring manual effort per message.
Personalization Engine
A personalisation engine is an AI-powered system that analyses subscriber data and behaviour to dynamically tailor email content, product recommendations, send times, and offers for each individual recipient at scale.
Personalization Techniques
Personalization techniques are the specific methods used to tailor email content to individual subscribers, from basic merge tags to advanced behavioural targeting.
Frequently Asked Questions
Each conditional block adds complexity and testing overhead. For most emails, 3–5 conditional blocks are manageable. Beyond that, consider whether you should segment the list instead and use simpler templates for each segment. Excessive conditional blocks increase the risk of errors and make troubleshooting difficult.
Conditional blocks render within your email as the content that was chosen for each recipient, so they appear as static content to the email client — meaning they work in all clients. Some live conditional content (AMP-based) has client limitations, but server-side conditional blocks work everywhere.