Plain text vs. HTML for B2B cold email:
what the data actually says.
One of the first practical questions in cold email is surprisingly simple: should the message look like a polished marketing email — logo, colors, images, buttons — or like something one person would send directly to another?
Our default is the second. For first-touch B2B outreach, we prefer a simple, text-first format. But the reason is not the usual myth that “HTML goes to spam.” The real answer is more nuanced: format affects technical complexity, recipient perception, tracking behavior, and the number of things competing with the reply.
The real question is not “HTML: yes or no?”
Most business email is technically HTML. Even a message that looks like plain text may be sent as HTML so it can support a signature, links, analytics, or formatting. So the useful distinction is not binary.
The practical question is: how much structure does the email need at this stage of the relationship?
Our working principle is simple: use the lightest format that can do the job. In a cold first touch, that job is usually to start a relevant conversation — not to reproduce a landing page inside the inbox.
Plain text, minimal HTML, and designed HTML are three different things
These formats should not be treated as interchangeable. A newsletter subscriber and a CFO receiving a first cold email are in very different relationship states, even if both messages arrive through the same inbox.
What do we actually know about deliverability?
It helps to separate observational evidence, performance tests, and provider guidance.
Hunter: a strong signal, but not proof of causation
Hunter analyzed 2.2 million cold emails and reported a major difference in bounce behavior between HTML and plain-text campaigns. In the data section of the study, the average bounce rate for HTML campaigns was reported as 652% higher than plain text.
That is relevant because the dataset comes directly from cold outreach. But Hunter also makes an essential methodological point: this was not a controlled A/B experiment. People who choose plain text may also verify addresses more carefully, send differently, use different lists, or follow different operational practices.
Correlation is not causation. The result is a reason to test format and keep the first touch light. It is not proof that HTML code, by itself, caused the bounces.
Hunter itself also notes that HTML is not inherently “bad.” The risk is more likely to emerge from the combination of structure, tracking, images, links, reputation, data quality, and sending behavior.
HubSpot: simpler often performs better, but the context is different
HubSpot's published tests are primarily about email marketing rather than cold outreach. That makes them useful for understanding how visual complexity can affect recipient behavior, but not direct evidence about cold-email deliverability.
Across more than ten A/B tests discussed in the article, simpler variants frequently outperformed richer ones. HubSpot reports examples where a simpler email produced 42% more clicks than a GIF version, an image-heavy HTML template generated 51% fewer total clicks, and a simpler HTML version produced 30% more clicks than the richer alternative.
There is an important technical footnote: several “plain-text” variants still included links and tracking pixels. They were visually simple, but not necessarily true text/plain email.
The useful takeaway is therefore not “HTML loses.” It is that reducing visual elements and making the email feel closer to normal one-to-one communication can improve recipient response in some contexts.
What Google and Microsoft say
Gmail's sender guidance does not list HTML as a negative factor by itself. Google focuses on authentication, message standards, spam rates, valid formatting, and — for high-volume senders — requirements such as DMARC and unsubscribe handling.
Microsoft likewise treats email as a MIME format that can carry plain text, HTML, or both. Its guidance emphasizes sound message construction and avoiding unnecessary complexity that creates rendering or delivery issues.
Format matters, but it is not the first deliverability variable. Authentication, reputation, data quality, relevance, complaint behavior, bounce rate, and sending stability are more foundational.
If your sender reputation is poor and your list is full of unverified addresses, removing the logo will not fix the campaign.
The other filter: how the recipient interprets the email
Inbox systems are not the only filter in cold outreach. The recipient is another — and often more important — one.
A person receiving a first message from an unfamiliar company makes a fast judgment about what kind of email it is. A large logo, hero image, and CTA button immediately resemble marketing. A short, restrained message looks more like the everyday communication people receive from colleagues, suppliers, customers, and business contacts.
That does not make simple email automatically credible. A generic, aggressive, obviously automated message is still generic and aggressive without images.
The opposite of a mass template is not plain text. It is relevance.
In Backlinko/Pitchbox's observational analysis of 12 million outreach emails, personalized subject lines were associated with a 30.5% higher reply rate, while personalized body copy was associated with a 32.7% higher reply rate. Those are correlations rather than causal proof, but they point toward something more important than decoration: recipient context.
Three levels of personalization
A simple email only works if the content itself deserves a conversation: the right prospect, real context, a clear reason for contact, and a message that respects the recipient's time.
Tracking and links: add only what has a job
Format is not only what the recipient sees. An open-tracking pixel loads a remote resource. Click tracking can introduce redirect domains. Every additional link gives the recipient another action besides replying.
Public evidence does not support a universal rule that “one link causes spam.” But for a first cold touch, a conservative default is straightforward: zero links when a reply is enough, or one link when it provides genuinely useful proof.
Website, calendar, case study, video, social links, and attachments all in the same first email usually add more friction than credibility.
It is not “plain text forever.” Use the right format at the right time.
Designed HTML has a role. It is simply better suited to some relationship stages than others.
The question should not be “How polished can we make this email?” It should be “What format reduces friction and makes the message easiest to understand at this stage of the relationship?”
Common mistakes
Using the marketing template for every message
Newsletter, lifecycle email, nurturing, and cold outreach are not just different versions of the same thing. In the first three, the recipient often already knows the brand. In cold outreach, you are trying to earn the relationship.
Confusing professionalism with design
Brand colors and buttons can look polished, but they do not make a first touch professional. In cold outreach, professionalism comes more from research quality, message precision, relevance, and respect for the recipient's time.
Blaming every deliverability problem on format
A plain-text email sent from a poor-reputation domain to unverified addresses does not become safe because it contains no HTML.
Optimizing only for open rate
Open rate is increasingly noisy as a standalone metric. Tracking pixels, privacy proxies, security prefetching, and image blocking can create false opens or hide real ones.
For cold outreach, reply rate, positive reply rate, meeting rate, bounce, complaint, and opt-out are usually more useful. Opens can remain a secondary diagnostic signal, not the commercial goal.
Why Outreach AI defaults to simple email
In our Outreach AI workflow, the message does not begin with a graphic template. It begins with the prospect: account, role, available context, recent signals, sequence history, and the knowledge of the company doing the outreach.
A simple format fits that model. If we have already done the work to understand why this person may be worth contacting, we want the message to be judged primarily on that relevance — not on whether the email looks like an ad.
The format should make room for context, not replace it.
This does not mean the product is technically locked to text-only email. It means our cold-outreach default is deliberately text-first. As the relationship becomes warmer — or the use case genuinely benefits from visual material, documentation, or richer branding — the format can change.
Sources and methodological notes
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Explore Outreach AI →For a first-touch B2B email, a simple one-to-one-looking message is often the safer default. Not because HTML is inherently bad, but because heavy templates, images, tracking, and multiple links add technical complexity and can make a cold message feel like a marketing campaign instead of a business conversation.
There is no universal rule that HTML equals spam. Gmail and other major providers support HTML email. Deliverability also depends on authentication, sender reputation, complaint rate, data quality, bounce behavior, and sending patterns. Some observational cold-email datasets show worse results for HTML campaigns, but they do not prove that HTML code alone caused the difference.
It is technically an HTML message but visually behaves like a normal personal email: mostly text, very few useful links, a simple signature, and no banners, decorative images, marketing layout, or oversized buttons. It is different from both true text/plain and a designed marketing template.
Designed HTML is more useful when the recipient already knows the brand or expects marketing communication: opt-in newsletters, lifecycle email, customer communication, visual content, or campaigns where the design genuinely helps explain the offer.
Because the first goal of cold outreach is not to showcase a brand through design. It is to start a relevant conversation. We therefore default to lightweight, context-driven messages and use richer formats when the relationship or use case gives them a clear job to do.
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