What is transactional email and what is it used for?

One of the questions we hear most often at Postmark is: what is transactional email, and how is it different from other types of email? Well, friends, seeing as we've been dealing with transactional email since 2009, we’re happy to answer that question in lots of detail and with plenty of examples.

What is transactional email? A definition  #

Transactional emails are messages that are sent in response to an action a user takes on a website or application. They contain data or content that is specific to that user, and are typically sent to individuals one at a time. Examples include:

• Password reset emails
• Account creation emails
• Welcome emails
• Shipping confirmations
• Payment invoices
• Purchase receipts
• Order confirmation emails
• Payment failure notifications

In general, recipients expect to receive transactional emails; and in many cases, they will actively refresh their inbox until the message arrives.

Transactional vs. marketing email #

Transactional emails contain user-specific content and are typically sent to individuals one at a time.

Marketing emails (also called promotional, broadcast, commercial, or bulk email) are mass distributions of the same message to many recipients simultaneously.

The most common types of marketing email include:

• Newsletters
• Limited-time offers
• Sales campaigns
• Event announcements
• Vouchers and giveaways

Most companies send both transactional and marketing emails, and rely on a combination of marketing automation, email marketing, CRM, and email delivery services to connect with their audience. It’s also possible to bring marketing, sales, and transactional messages together in one platform.

💡 Since Postmark is part of ActiveCampaign, we recommend taking them for a spin if you’re looking to manage all your emails in a single place.

You can see the difference summarized in this image:

Most companies send both transactional and marketing emails, and the distinction matters more than many people realize. These two categories serve very different purposes, follow different delivery patterns, and are evaluated differently by inbox providers.

For this reason, many teams rely on a combination of tools: marketing automation, email marketing, CRM, and email delivery services to connect with their audience. Increasingly, though, it’s necessary for those systems to work together seamlessly, and it’s also possible to bring marketing, sales, and transactional messages together in one platform.

💡 Postmark is part of ActiveCampaign, so we recommend taking them for a spin if you’re looking to manage all your emails in a single place.

Integrating the Postmark and ActiveCampaign platforms lets you send high-priority transactional emails through Postmark while continuing to manage campaigns, automations, and customer data inside ActiveCampaign. They help contact data work in sync, so you won’t have to duct-tape multiple systems together. Later in this article, we’ll walk through the best scenarios for connecting your transactional and marketing email strategies.

Personal sidenote: spotting the differences between a transactional and a marketing email can be tricky, even for someone who’s been working in email for 15+ years (me!).

Prior to joining the Postmark team, I used to think that any email that didn’t require an unsubscribe link was a transactional email. But it turns out receivers like Gmail and Yahoo look at email differently than I do: they pay an awful lot of attention to the content (is it specific to that user?) and how the message is distributed (to many people at once, or one person at a time?) when determining whether or not an email belongs in the “bulk” category.

A few practical best practices for telling the difference:

• Ask why the email exists. Is it required for the user to complete an action or understand something about their account? Or is it trying to influence behavior (click, buy, attend, upgrade)?
• Look at personalization depth. True transactional emails are deeply specific to one user (their order, their account, their activity), not just “Hi {{first name}}.”
• Check distribution patterns. Sending the same or very similar messages to thousands of recipients at once (even if it’s “important”) often looks like marketing to inbox providers.
• Separate critical signals from promotions. Adding upsells, cross-promotions, or CTAs to a transactional email can push it into marketing territory.
• Design for clarity, not conversion. Transactional emails prioritize information and confirmation over persuasion.

Here is a quick clip of me talking about the difference between transactional and marketing email, if you'd like to hear my voice instead of just reading my words:

What is transactional email used for? 5 use cases #

Transactional emails are the foundation of most online businesses, connecting them to individual users and customers. 

These emails are often treated as the ‘set it and forget it’ notifications that website and product owners must implement so the business can function, but do not underestimate their larger impact on customer experience and retention.

If you’ve ever been locked out of an account and waited for a password reset email that never came, you’ll know how a simple missing email can be the source of great frustration.

Although this is not a comprehensive list, we tend to group transactional emails into:

1. Emails that help manage user accounts and logins
2. Emails that are directly tied to payment processes 
3. Emails that are triggered by specific events 
4. Emails that deliver content a user requested 
5. Emails that deliver useful updates and insights about product usage
 

1. Emails that help manage user accounts and logins #

Examples: account created, welcome email, password reset, 2FA enablement, magic sign-in links, new login attempt notifications, new user added, trial expiring.

This category of transactional email covers the notifications sent to users and customers when they create and manage an account with a provider. These emails include the initial welcome notification a user gets when signing up, and the password resets or magic link messages they receive if they forget their credentials. Account-related emails also include all the notifications sent to an admin to alert them of new people/teammates joining the account or trials expiring.

2. Emails that are directly tied to payment processes #

Examples: invoices, receipts, payment failure (dunning), credit card expiration, subscription upgrade/downgrade/cancellation/renewal.

Some of the most well-known transactional emails are the ones tied to a transaction (hence the name). For example, when customers make a purchase online, they’ll usually receive an order confirmation and/or a receipt; if a recurring payment fails or there are issues with payment processing, they might receive a payment failure notification (known as a dunning email) instead.

3. Emails that are triggered by specific events #

Examples: comment notifications, event reminders, calendar notifications, shipping confirmations and updates.

These types of transactional emails are similar to mobile phone push notifications, but they happen in an email inbox instead.

Unlike the other transactional emails we’ve seen so far, event-driven notifications aren’t typically triggered by an action taken by the recipient; instead, these notifications can let the recipient know about something that has happened (e.g. they have been tagged in a social media post or a package they’re expecting has been shipped or delivered) or remind them of something happening soon (e.g. the concert they purchased tickets for is coming up tomorrow).

4. Emails that deliver content a user requested #

Examples: data exports, itinerary details, return labels.

These types of transactional emails contain information that a user has explicitly requested as part of their product or website experience. There are hundreds of requests that can fall under this category: from CSV or data export/download to return labels, from flight itinerary details to e-books, PDFs, or any other downloadable goods a user wants to receive. 
 

5. Emails that deliver useful updates and insights about product usage #

Examples: summaries, reports, digests

This category includes summaries, reports, and digests for users who want to stay on top of important notifications without cluttering their inbox with individual emails. Some of these emails can be straightforward logs of the events that have occurred during a specific timeframe (e.g. daily, weekly, or monthly account activity information); others can even act as an extension of the product experience, and be rich with personalized content.

💛 Pro tip: most folks in the industry consider reports and digests transactional, which is why we included them here—but if you are using Postmark to send this specific format of email, we recommend sending it over a Broadcast Stream instead. 

When transactional and marketing email do work together #

Transactional and marketing emails are usually kept apart—and for good reason.

They have different jobs, different rules, and different delivery requirements. Transactional emails must be fast, predictable, and rock-solid. They need to arrive immediately and reliably, even during traffic spikes. Marketing emails are sent in batches, include opt-outs, and aim to persuade or nurture over time. Blurring those lines can hurt deliverability, compliance, and trust.

So yes, sending should be separate. Separation at the sending layer still matters.

But that doesn’t mean everything else should. Separation doesn’t have to mean isolation.

When transactional and marketing systems don’t talk to each other, things get awkward. Follow-ups arrive late. Messages feel generic. Customers wonder if anyone’s really paying attention.

Transactional emails often represent a user’s clearest signals: a signup, a purchase, an upgrade, a reset. Marketing and lifecycle emails are most effective when they can react to those signals quickly.

When you coordinate these two strategies, you can share context between the systems to make customer communication feel more connected and good things happen:

• Smarter, timelier marketing
  Real user actions trigger relevant follow-ups—no waiting, no guesswork.
• A consistent voice, end to end
  From receipt to onboarding to lifecycle emails, your brand sounds like one team, not five tools.
• Less friction, fewer handoffs
  Product events flow naturally into communication without duct tape or manual syncs.
• A clearer view of the customer journey
  You see how transactional and marketing touchpoints connect—and where they don’t.

This is exactly why pairing Postmark and ActiveCampaign works so well. Postmark handles critical transactional delivery with speed and reliability, while ActiveCampaign orchestrates the broader customer journey—using the same signals that power your product.

How to integrate transactional and marketing email strategy with Postmark + ActiveCampaign #

You might be looking at this notion of an “integrated transactional and marketing email strategy” suspiciously, imagining marketing content sneaking into password resets.

Don’t worry. That’s not what we mean.

Integration of transactional and marketing emails means letting the systems that power them share context. In practice, that looks like this:

• Shared customer data
   Key events and attributes flow between systems so both understand what a user just did.
• Event-driven automation
   Real actions (signups, purchases, upgrades) trigger the right follow-up at the right time.
• Coordinated timing and intent
   Messages feel connected and purposeful—not repetitive or out of sync.

What it does not mean is:

• Adding bonus promotions to receipts
• Turning transactional emails into mini campaigns
• Skipping consent or compliance rules

Best practices still apply. Transactional emails should remain purely transactional. Marketing emails should remain permission-based, opt-out friendly, and thoughtfully timed.

Postmark and ActiveCampaign are designed to solve this problem together—on purpose.

• ActiveCampaign acts as the system of record for customer data, preferences, segmentation, and automation logic.
• Postmark is the delivery layer for fast, reliable transactional email, built to handle critical messages without delay or deliverability drama.

Because Postmark is part of ActiveCampaign, the teams work closely to ensure the integration is seamless, compliant, and reliable. You get best-in-class deliverability on both sides, without stitching together tools that were never meant to cooperate.

Here’s what an integrated, but properly separated, setup might look like through the Postmark + ActiveCampaign integration:

1. A user signs up for your product.
2. Postmark immediately sends the account confirmation email.
3. That signup event updates ActiveCampaign with fresh customer data.
4. ActiveCampaign triggers a tailored onboarding or educational sequence, based on the user’s preferences and consent.
5. Transactional and marketing messages feel timely, relevant, and coordinated—without stepping on each other’s toes.

No duplicated emails. No awkward timing. No mixed messages.

That’s the sweet spot: transactional email that does its job flawlessly, and marketing email that knows exactly when—and how—to follow up.

Final thoughts + transactional email resources #

Whether you have a small team with a mobile application or a robust e-commerce company with thousands of products, transactional emails can greatly benefit your business—provided they get delivered reliably and are clear to follow. If crucial emails are delayed, keep landing in the spam folder, or are just not working as intended, your customers’ loyalty to your business might eventually come to an end.

At Postmark, we’re passionate about transactional email and the importance of doing it right—it was our sole focus for our first decade as a company. Over the years, we collected a lot of resources you might find useful right now:

• To send transactional emails quickly and reliably, you need a trustworthy provider with excellent deliverability. If you don't know how to choose between the many available delivery services, start by comparing the pros and cons of the 6 top transactional email services including Postmark (hi 👋), Amazon SES, and Mandrill by Mailchimp. 

• If you'd like to learn more about optimizing your transactional email, check out our extensive email design guides and our deep dive into transactional email best practices: they will teach you everything you need to know to create beautiful and effective transactional emails.

• If you need inspiration and practical advice, follow the link to see some transactional email examples from our team—these are the emails we send out from Postmark, using Postmark, to grow our business and keep our customers happy.

• And finally: if you're looking to send transactional emails but don’t know where to start, here are ten free and open-source transactional email templates for your business you can simply copy-paste and start using today.

After reading this article, you should know... #

What is a transactional email? #

Transactional email is a type of automated, non-promotional email that is triggered by events, interactions, or preferences within a service and is delivered to individuals one at a time.

What is the difference between transactional and marketing email? #

Transactional emails contain user-specific content and are sent to individuals one at a time. Marketing emails, also called bulk or promotional emails, are mass distributions of the same message to many recipients simultaneously—including newsletters, limited-time offers, or sales campaigns.

What are the most common types of transactional email? #

The most common types of transactional email you might have received (or sent) include:

• Password reset emails
• Account creation emails
• Welcome emails
• Shipping confirmations
• Payment invoices
• Purchase receipts
• Order confirmation emails
• Payment failure notifications

Who is the best transactional email provider? #

What separates an average service provider from a great one may depend on what you and your business need when it comes to your transactional emails. The most renowned players in the space include Postmark (hi!), Amazon SES, SendGrid, MailGun, and Sparkpost.