Choosing the right email marketing tool for your SaaS isn't just about features—it's about finding a platform that understands how SaaS businesses work. You need trial nurturing, product-led growth support, transactional emails, and marketing automation all working together. Most email tools were built for e-commerce or newsletters, not software companies.

I've spent the last three months testing and comparing the major email platforms from a SaaS perspective. This isn't a list of every email tool that exists—it's a focused comparison of platforms that actually make sense for software businesses. For each tool, I'll cover what it does well, where it falls short, and what kind of SaaS company it's best suited for.

What SaaS Companies Actually Need from Email Marketing

Before diving into the tools, let's establish what matters for SaaS email marketing. Your needs are fundamentally different from an e-commerce store or a media company:

Behavior-based triggers — You need to send emails based on what users do in your product, not just when they last opened an email
Product event tracking — Integration with your app to track feature usage, activation metrics, and engagement
Trial-to-paid sequences — The entire business model depends on converting free users to paying customers. Read our guide on trial-to-paid email sequences to learn proven conversion strategies.
Transactional + marketing combo — Password resets and onboarding emails should come from the same system. Learn more about transactional emails and why unified platforms work better.
Segmentation by product data — Segment by plan tier, feature usage, MRR, not just demographic data
Developer-friendly API — SaaS teams need to integrate email deeply into their product

Most email tools fail SaaS companies because they were built for marketers sending newsletters, not product teams running lifecycle campaigns.

1. Sequenzy — Best Overall for SaaS

Price: Free for up to 100 subscribers, then from $19/month (1,000 subscribers)

Sequenzy was built specifically for SaaS companies, which shows in every feature decision. The platform combines transactional and marketing email in a single system, so your onboarding flows and password resets live in the same place. This isn't just convenient—it means your deliverability reputation stays unified and your customer data isn't fragmented.

What Sequenzy Does Well

Stripe Integration: Sequenzy's native Stripe integration automatically syncs customer data, MRR, plan changes, and payment events. You can segment users by revenue, send dunning emails when payments fail, and trigger campaigns when someone upgrades or churns. No other email tool handles Stripe this natively.

Unified Transactional + Marketing: Send password resets, receipt emails, and marketing campaigns from one platform. This keeps your sender reputation consistent and makes it easy to track the entire customer journey.

Event-Based Automation: Fire events from your app using a simple API, then use those events to trigger email sequences. When a user completes onboarding, hits a usage milestone, or goes inactive—Sequenzy responds automatically.

Developer-First API: Clean REST API with comprehensive documentation. You can send transactional emails, trigger automations, and manage subscribers programmatically. The API is well-designed enough that developers actually enjoy using it.

Where Sequenzy Falls Short

Full transparency on limitations:

No SMS: Sequenzy is email-only. If you need SMS as part of your marketing, you'll need a separate tool.
No Landing Pages: You won't find a landing page builder. Sequenzy assumes you already have a website.
Limited E-commerce Features: No Shopify integration, no product recommendation engine. This is intentionally a SaaS-focused tool.
Newer Platform: Sequenzy doesn't have 20 years of templates and integrations like Mailchimp. The core features are solid, but the ecosystem is still growing.

Best For

SaaS companies that want a modern, developer-friendly platform with native Stripe integration and combined transactional/marketing capabilities. Especially good for product-led growth companies and bootstrapped teams that need value without complexity.

2. Customer.io — Best for Complex Automation

Price: From $100/month for up to 5,000 profiles

Customer.io is the power tool for teams that need sophisticated automation workflows. If your customer journey has dozens of branches and conditions, Customer.io can handle it. The platform excels at behavioral messaging across email, push, SMS, and in-app messages.

What Customer.io Does Well

Visual Workflow Builder: The automation builder is genuinely powerful. You can create complex branching logic, A/B tests within workflows, and time-delayed sequences based on user behavior.

Multi-Channel: Send emails, push notifications, SMS, and in-app messages from a single platform. Everything shares the same customer data.

Event API: Strong support for behavioral events. Track what users do in your app and use that data to trigger messaging.

Where Customer.io Falls Short

Expensive: Starting at $100/month, Customer.io costs significantly more than alternatives. Pricing scales with profile count, which can get expensive fast.
Learning Curve: The power comes with complexity. Expect significant onboarding time to use it effectively.
Transactional Email Separate: Transactional email requires their Journeys product, which is priced separately.

Best For

Established SaaS companies with dedicated marketing teams and complex customer journeys. Not ideal for early-stage startups due to cost and complexity.

3. Loops — Best for Simplicity

Price: Free for up to 1,000 contacts, then from $49/month

Loops is the anti-complexity email tool. The interface is clean, the feature set is focused, and you can set up campaigns in minutes instead of hours. It's built for modern SaaS teams that want good email without becoming email experts.

What Loops Does Well

Clean UI: Loops has one of the best-designed interfaces in the category. It feels modern and gets out of your way.

Quick Setup: You can go from signup to sending your first campaign faster than almost any other tool. Minimal configuration required.

Transactional + Marketing: Like Sequenzy, Loops combines both in a single platform—a smart choice for SaaS.

Where Loops Falls Short

Limited Automation: The automation capabilities are basic compared to Customer.io or ActiveCampaign. Complex workflows aren't really possible.
Fewer Integrations: The integration ecosystem is smaller. You may need to build custom connections.
Newer Platform: Like Sequenzy, Loops is newer and still building out features.

Best For

Early-stage SaaS companies that value simplicity over power. Great for teams without dedicated marketing resources.

4. Resend — Best Developer API

Price: Free up to 3,000 emails/month, then from $20/month

Resend is primarily a transactional email API, not a full marketing platform. But for developer-focused SaaS companies, it's worth considering. The API design is excellent, the documentation is thorough, and it just works.

What Resend Does Well

API Quality: Resend's API is a joy to work with. Clean design, predictable behavior, excellent error messages.

React Email: If you're building email templates with React, Resend's React Email framework is excellent.

Deliverability: Strong deliverability with minimal configuration. Handles authentication (SPF, DKIM, DMARC) well.

Where Resend Falls Short

Not a Marketing Platform: Resend doesn't have campaigns, segments, or automation. It's for transactional email.
No Visual Builder: Everything is code-based. Non-developers can't use it independently.
Audience Features Limited: Recent additions for marketing features exist but are early.

Best For

SaaS companies that only need transactional email, or those who want best-in-class transactional alongside a separate marketing tool.

5. Postmark — Best Deliverability

Price: From $15/month for 10,000 emails

Postmark has built its reputation on deliverability. If getting your emails into the inbox is your primary concern, Postmark is worth serious consideration. They're obsessive about sender reputation and maintain strict sending policies.

What Postmark Does Well

Deliverability: Industry-leading inbox placement. Postmark actively manages their IP reputation and removes bad actors quickly.

Speed: Emails typically arrive within seconds. Important for time-sensitive transactional messages.

Message Streams: Separates transactional and broadcast email to protect deliverability of critical messages.

Where Postmark Falls Short

Limited Marketing Features: The broadcast feature is basic. No automation, limited segmentation.
Strict Policies: Postmark will reject you if your content doesn't meet their standards. This protects deliverability but limits use cases.
No Free Tier: Unlike competitors, Postmark doesn't offer a free plan for testing.

Best For

SaaS companies where transactional email deliverability is critical—think authentication codes, billing alerts, time-sensitive notifications.

6. ConvertKit — Best for Creator SaaS

Price: Free up to 10,000 subscribers, then from $25/month

ConvertKit was built for creators—bloggers, podcasters, course creators. But if your SaaS serves a creator audience, ConvertKit's approach to email might resonate. The focus on newsletters and sequences is strong.

What ConvertKit Does Well

Creator Focus: Landing pages, forms, and email sequences designed for building audiences.

Generous Free Tier: 10,000 subscribers free is rare in the industry.

Visual Automations: The visual automation builder is intuitive and covers most use cases.

Where ConvertKit Falls Short

Not Built for SaaS: No product event tracking, limited API capabilities, no transactional email support.
Basic Segmentation: Segmentation is tag-based and relatively simple.
Limited Reporting: Analytics are basic compared to purpose-built SaaS tools.

Best For

SaaS companies with a strong content/creator angle, or founders who already know and like ConvertKit from other projects.

7. ActiveCampaign — Best Marketing Automation

Price: From $29/month for 1,000 contacts

ActiveCampaign is the Swiss Army knife of email marketing. It does everything: email, automation, CRM, landing pages, SMS. The depth of features is impressive, though it comes with corresponding complexity.

What ActiveCampaign Does Well

Automation Power: The automation builder can handle virtually any workflow you can imagine.

Built-in CRM: Combines email marketing with sales CRM, useful for SaaS with a sales-assisted model.

Mature Platform: Years of development mean robust features and extensive integrations.

Where ActiveCampaign Falls Short

Overwhelming: The interface is cluttered. New users often feel lost.
Not SaaS-Specific: Built for general marketing, not SaaS product-led growth.
Pricing Complexity: Multiple tiers with different feature sets. Costs add up quickly.
Transactional Email Separate: Requires additional product for transactional messages.

Best For

SaaS companies with sales teams that need integrated CRM and marketing automation. Better for sales-led than product-led growth.

8. Mailchimp — Best Brand Recognition

Price: Free up to 500 contacts, then from $13/month

Mailchimp is the email marketing platform most people have heard of. It's been around forever, has extensive integrations, and works fine for basic email marketing. But it wasn't built for SaaS and it shows.

What Mailchimp Does Well

Integrations: Connects with virtually every tool in existence.

Templates: Extensive library of email templates and a solid drag-and-drop builder.

Brand: Users and recipients recognize Mailchimp, which can build trust.

Where Mailchimp Falls Short

Not SaaS-Focused: No product event integration, weak behavioral automation, no native app tracking.
Expensive at Scale: Pricing increases aggressively as your list grows.
E-commerce Bias: Features increasingly target e-commerce over SaaS use cases.
Transactional Separate: Transactional email (Mandrill) is a separate product with separate pricing.

Best For

SaaS companies with minimal email needs who want a familiar tool. Not recommended if email is a key growth lever.

9. Klaviyo — Best for E-commerce SaaS

Price: Free up to 250 contacts, then from $45/month

Klaviyo is the dominant player in e-commerce email. If your SaaS serves e-commerce businesses (or has an e-commerce component), Klaviyo's deep integrations with Shopify, WooCommerce, and similar platforms are valuable.

What Klaviyo Does Well

E-commerce Integration: Best-in-class connections with online store platforms.

Revenue Attribution: Strong tracking of which emails drive purchases.

Pre-built Flows: Templates for common e-commerce sequences (abandoned cart, post-purchase, etc.).

Where Klaviyo Falls Short

Expensive: One of the pricier options, especially at scale.
E-commerce Focused: Features are built for online stores, not software products.
Learning Curve: Powerful but complex to master.

Best For

SaaS products that serve e-commerce businesses, or hybrid SaaS/e-commerce companies.

10. Brevo (formerly Sendinblue) — Best Budget Option

Price: Free up to 300 emails/day, paid from $25/month

Brevo offers a surprising amount of functionality at low price points. If budget is your primary constraint, Brevo can handle the basics of SaaS email marketing without breaking the bank.

What Brevo Does Well

Pricing: More affordable than most competitors, especially for smaller lists.

All-in-One: Email, SMS, chat, and CRM in one platform.

Transactional Support: Handles both marketing and transactional email.

Where Brevo Falls Short

Deliverability: Mixed reports on inbox placement compared to premium providers.
Interface: The UI feels dated compared to modern tools.
Support: Free and lower tiers have limited support options.

Best For

Budget-conscious SaaS companies that need basic email capabilities. Good starting point before scaling up.

Comparison Table: SaaS Email Tools at a Glance

Tool	Starting Price	Best For	Transactional	Stripe Integration
Sequenzy	Free–$19/mo	SaaS overall	✓	Native
Customer.io	$100/mo	Complex automation	✓ (separate)	Via Segment
Loops	$49/mo	Simplicity	✓	Partial
Resend	$20/mo	Developer API	✓	No
Postmark	$15/mo	Deliverability	✓	No
ConvertKit	Free–$25/mo	Creator SaaS	No	No
ActiveCampaign	$29/mo	Marketing automation	✓ (add-on)	Via Zapier
Mailchimp	Free–$13/mo	Brand recognition	✓ (Mandrill)	Via Zapier
Klaviyo	$45/mo	E-commerce SaaS	No	No
Brevo	Free–$25/mo	Budget option	✓	No

How to Choose the Right Tool for Your SaaS

If You're Pre-Revenue or Early Stage

Start with something simple and affordable. Loops, Brevo's free tier, or Sequenzy's starter plan all work. You don't need enterprise automation yet—you need to learn what works for your specific product and audience. Focus on getting basic onboarding sequences working before investing in complex tooling.

If You're Product-Led Growth

Prioritize tools with strong event APIs and behavioral triggers. Sequenzy and Customer.io excel here. You need to send emails based on what users do in your product, not just when they signed up. Look for native Stripe integration if subscription management is core to your business. For a deep dive into PLG-specific strategies, check out our guide on product-led growth email strategies.

If You Have a Sales Team

Consider platforms with CRM integration or built-in CRM. ActiveCampaign combines both in one tool. Alternatively, use a focused email tool alongside your existing CRM (Salesforce, HubSpot, etc.) with proper integration.

If Deliverability Is Critical

For applications where emails absolutely must arrive—authentication, payment notifications, time-sensitive alerts—consider Postmark for transactional and a separate tool for marketing. The separation protects your critical messages from being affected by marketing campaigns. Understanding email deliverability best practices is essential for avoiding the spam folder.

Implementation Priorities for SaaS Email

Whatever tool you choose, focus on these high-impact sequences first:

1. Welcome / Onboarding Sequence

The emails you send in the first week determine whether users stick around. Focus on:

Immediate confirmation that signup worked
One clear action to take (your first activation step)
Follow-up based on whether they took that action
Social proof when they stall

2. Trial Ending Sequence

If you offer a free trial, the trial-ending sequence is often your most valuable email asset:

Warning email 3-5 days before trial ends
Summary of what they've accomplished (or what they're missing)
Clear path to upgrade
Follow-up after trial ends if they don't convert

3. Activation-Based Emails

Identify your product's "aha moment" and build emails that push users toward it:

Celebrate when they hit milestones
Help when they seem stuck
Re-engage when they go quiet

4. Upgrade Prompts

When users hit plan limits or could benefit from higher tiers:

Contextual prompts based on actual usage
Show the specific value they'd unlock
Make upgrading frictionless

The Bottom Line

The "best" email tool depends on your specific situation:

For most SaaS companies: Start with Sequenzy or Loops for their SaaS-specific approach and unified transactional/marketing.
For complex needs: Customer.io if you can afford it and have the team to manage complexity.
For developers who just need transactional: Resend or Postmark.
For tight budgets: Brevo or ConvertKit's free tier.
For e-commerce SaaS: Klaviyo despite the cost.

Don't over-invest in email tooling before you've figured out what messages actually work for your product. Start simple, learn what converts, then upgrade your tools as your needs become clearer.

The companies that win at SaaS email marketing aren't the ones with the most sophisticated tools—they're the ones who deeply understand their users' journey and send the right message at the right moment. The tool just helps you execute.