When to use plain text and when to use HTML
Ecommerce founders ask me all the time whether they should send heavily designed HTML templates or stripped-back plain text emails. Most brands default to full HTML for every single message because they think polished graphics look more professional. That is a mistake.
There is no universal winner between the two formats. What works best depends entirely on the intent of the message. In my experience, plain text excels at conveying genuine emotion, personal connection, and gratitude. HTML wins when you need visual merchandising to drive immediate product desire.
If you treat email format as an intentional lever rather than a cosmetic default, your metrics will reflect it. Here is the framework I use across our client accounts to decide where each format belongs.
Why sunset flows belong in plain text
A sunset flow is designed to re-engage subscribers who have stopped opening your emails before you finally suppress them. When someone has ignored your standard visual campaigns for 60 to 90 days, sending yet another promotional banner will not change their mind.
I build almost every sunset flow email in plain text. A message that looks like a personal note from the founder cuts through inbox clutter far better than another catalog spread. It feels like a real person reaching out rather than a broadcast engine.
In our client accounts, switching sunset flows from HTML to plain text routinely lifts open rates by roughly 15% to 25%. When deliverability is on the line, plain text delivers the cleanest signal to mailbox providers that a 1-to-1 conversation is happening.
The post-purchase founder thank you
Another place where plain text outperforms designed templates is the post-purchase thank you flow. Specifically, I use a trigger split where placed order equals 1 over all time to speak directly to first-time buyers right after they purchase.
This email is signed off by the brand owner. It says something simple: thank you for supporting an independent business, we appreciate your order, and our team is already getting it ready. If there is no first name on file, Klaviyo defaults to a clean greeting without breaking the conversational tone.
There are zero product blocks, zero coupon codes, and zero creative banners in this email. We are not trying to sell here. We are trying to endear the customer to the brand, build loyalty, and lay the groundwork for repeat purchases later.
Review requests and milestone messages
Review flows and customer feedback requests are another sweet spot for plain text. When a customer receives a standard marketing template asking for a review, it feels like an automated administrative chore. When they receive a simple text note asking how the product worked out, response rates climb.
The same logic applies to end-of-year brand messages and milestone updates. A quick note in December saying goodbye to the year and thanking customers for supporting the business lands far better in plain text. It makes the reader feel valued rather than targeted.
You can include a single hyperlinked line for the review portal or store link. Keep the surrounding layout completely bare.
Where HTML still wins the sale
Plain text has immense power, but visual HTML templates are still essential for ecommerce revenue. When your primary objective is cross-selling or launching a new collection, customers need to see what they are buying.
I use HTML layouts with high-quality creative assets for:
- Product cross-sell and upsell recommendations based on past purchase categories
- Browse abandonment flows showcasing the exact SKU viewed
- Promotional campaign drops, seasonal sales, and product launches
- Back-in-stock notifications where product photography drives instant intent
Visual emails give you control over hierarchy, typography, and clear call-to-action buttons. When you want to sell products, HTML works best. When you want to build relationships, plain text wins.
Final Thoughts
Email marketing is not an all-or-nothing choice between pretty templates and raw text. Use plain text in your sunset flows, founder thank you notes, and review requests to drive intimacy and open rates. Reserve HTML for product discovery, seasonal campaigns, and visual cross-sells where the product needs to do the talking.
Next steps for your email flows
If your automated flows rely on one generic template across every touchpoint, you are leaving engagement and revenue on the table. Explore our email automation services to see how we build high-converting, tailored Klaviyo flow architecture for scaling ecommerce brands.
