Best SendGrid alternatives for email, push, in-app, and messaging 

SendGrid has been part of the email infrastructure landscape for years. Today, Twilio SendGrid offers an Email API for programmatic sending alongside tools for email marketing, templates, deliverability, analytics, and more.

And it operates at a serious scale. SendGrid says its Email API handles more than 148 billion emails every month. But scale isn't the only thing that matters when choosing a customer messaging platform.

Your customers don't live exclusively in their inboxes. They use your product, check their phones, respond to push notifications, read SMS messages, and move between channels throughout the customer lifecycle.

That creates an important distinction when evaluating SendGrid alternatives:

Do you need a different way to send email, or do you need a different way to communicate with customers?

The best SendGrid alternatives include Customer.io, Resend, Postmark, Mailgun, Braze, OneSignal, and Courier. Resend, Postmark, and Mailgun are strong options when email infrastructure remains the primary requirement. Courier is designed around a developer-focused notification infrastructure. Braze, OneSignal, and Customer.io expand the comparison into multi-channel customer engagement.

Here's how they compare.

*Capabilities may span Mailgun's broader product portfolio.

If you primarily need to replace SendGrid's email infrastructure, start with Resend, Postmark, or Mailgun. If your requirements have expanded into behavioral targeting, push notifications, in-app messaging, and lifecycle automation, Customer.io, Braze, and OneSignal are more relevant comparisons.

If developers are building notification experiences directly into your product, Courier belongs on the shortlist.

SendGrid solves an important problem: sending email at scale.

Its Email API supports REST APIs and SMTP, dynamic templates, authentication, email validation, testing, analytics, and other tools for managing an email program.

For plenty of organizations, that's exactly the infrastructure they need.

But teams often start looking for SendGrid alternatives when the problem they're trying to solve gets bigger than email delivery.

Consider the different moments when a customer might hear from your company:

• An account verification arrives by email.
• An important account update triggers a push notification.
• A new feature is introduced inside your app.
• A time-sensitive reminder arrives by SMS.
• An abandoned onboarding flow triggers a personalized email.
• A customer who completes an important action moves into a different lifecycle journey.

Email might play a role in almost all of those experiences, but it doesn't have to play the only role.

In Customer.io's 2026 state of customer messaging, more than 750 marketers, product managers, growth professionals, engineers, and operations leaders shared how their teams communicate with customers. While every respondent used email, 42% also used in-app messages, 36% used SMS, and 30% used mobile push notifications.

That's why even though email is important, it shouldn't be the entirety of your messaging architecture.

Transactional email and lifecycle marketing solve different problems.

A password reset is needed because someone requested it. A re-engagement email exists because someone's behavior suggests they might need a reason to return.

But the person receiving those messages is still the same customer.

As your messaging program becomes more sophisticated, you may want the context surrounding those interactions to travel with them.

Imagine someone signs up for your product and then:

1. Verifies their account.
2. Completes two onboarding steps.
3. Leaves before completing the third.
4. Returns on mobile two days later.
5. Uses an important feature for the first time.
6. Upgrades to a paid plan.

Each action tells you something.

A messaging platform that understands those behaviors can do more than simply deliver the next email. It can use them to determine whether a message should be sent, what it should say, when it should arrive, and which channel makes the most sense.

Traditional email infrastructure generally begins with an instruction:

Send this email.

Lifecycle orchestration begins earlier:

This customer just did something. What should happen next?

That distinction changes what you need from your technology.

The 2026 customer messaging trends data found that attribute-based segmentation and behavioral triggers were the two personalization tactics that marketers most frequently identified as delivering the best ROI.

When behavior becomes the trigger, your messaging platform needs to understand more than an email address. It needs customer context.

Developers may own transactional integrations while lifecycle marketers build onboarding, activation, retention, and expansion programs. Product teams might own in-app experiences. Growth teams may run experiments across several of them.

That division of responsibility is normal.

The friction comes when each team has a different understanding of the customer because the messaging stack is fragmented across disconnected tools.

A broader customer engagement platform can give different teams ways to work with the same underlying customer attributes and behavioral data while still owning different parts of the experience.

Looking for a SendGrid alternative doesn't necessarily mean you're trying to move beyond email.

You may simply be reconsidering your email infrastructure.

If deliverability is driving the evaluation, remember that switching providers isn't a magic fix. Authentication, sender reputation, list quality, engagement, sending patterns, and spam complaints all influence whether your messages actually reach the inbox.

Our recent guide to improving email deliverability walks through those factors, and the practical steps teams can take to build stronger sender trust.

That means evaluating a provider's deliverability tooling and expertise is important, but so is understanding the health of your own sending program.

Best for: Teams that want customer data, transactional messaging, and lifecycle automation working together across channels.

Customer.io approaches messaging from a different starting point than SendGrid.

Rather than centering the platform primarily around email infrastructure, Customer.io connects customer data with messaging and automation.

That means teams can use behavioral events and customer attributes to trigger and personalize journeys across channels, while also handling programmatically triggered transactional messages.

Customer.io supports channels including:

• Email
• Mobile push
• In-app messaging
• SMS
• WhatsApp
• Webhooks

The result is a messaging layer that can respond to what customers actually do.

Imagine a customer starts a free trial.

Instead of simply enrolling everyone in the same email sequence, you might:

1. Send a welcome email.
2. Stop onboarding reminders if they complete setup.
3. Show an in-app tip based on the feature they're currently using.
4. Send a push notification if a time-sensitive event occurs.
5. Branch the journey when they reach an activation milestone.
6. Trigger a different experience when they upgrade.

The messages aren't independent campaigns. They're responses to a changing customer state.

*Twilio offers additional communication products outside SendGrid.

Twilio, as a company, offers more than email. But SendGrid itself is Twilio's email platform. Using additional Twilio products can expand your communications stack, but that isn't the same as SendGrid natively functioning as a cross-channel lifecycle platform.

Choose Customer.io if: You want customer behavior, segmentation, transactional messages, and lifecycle journeys working together across email, push, in-app, SMS, and other channels.

Consider SendGrid if: Your core requirement is scalable email infrastructure, and your application or surrounding stack will handle most orchestration.

Best for: Developers who want a focused API-first approach to sending email.

Resend is one of the newer SendGrid alternatives, built explicitly around developer experience.

It offers transactional email through a REST API, SDKs, and SMTP, along with domains, templates, webhooks, observability, inbound email, and other email tooling.

Resend has also expanded beyond purely transactional email with features for Broadcasts, Audiences, and Automations.

That makes it an interesting SendGrid alternative for teams that aren't trying to leave email behind. They simply want a different developer experience for building with it.

The comparison largely comes down to what you value in your email infrastructure.

SendGrid brings years of scale, a mature feature set, extensive email infrastructure, and the surrounding Twilio ecosystem. Resend emphasizes a streamlined, modern developer experience.

Neither solves the broader cross-channel orchestration problem by itself.

Choose Resend if: You primarily need email and want a developer-first API and SDK experience.

Consider another option if: You're replacing SendGrid because you want push, in-app messaging, and behavior-driven lifecycle journeys in the same platform.

Want a deeper comparison? We've also broken down the best Resend alternatives for email, push, and in-app messaging.

Best for: Teams that want to keep transactional email infrastructure focused and straightforward.

Postmark is another direct SendGrid alternative when the requirement is primarily transactional email.

Its platform focuses on application email, with API and SMTP sending, templates, webhooks, analytics, and Message Streams for separating different categories of email traffic.

That narrower scope can be an advantage.

Not every organization needs its transactional email provider to become its lifecycle marketing platform.

SendGrid covers both transactional email and email marketing use cases.

Postmark has historically put much more emphasis on application and transactional email.

If you're currently using SendGrid primarily for password resets, receipts, notifications, confirmations, and other application-generated emails, Postmark deserves consideration.

If SendGrid is also powering substantial marketing automation, you'll need to consider what replaces that part of your stack.

Choose Postmark if: Transactional email is the main problem you're solving.

Consider another option if: You want transactional and lifecycle messaging orchestrated across several channels.

Best for: Engineering teams that want API-driven email infrastructure and deliverability tooling.

Mailgun is another longstanding SendGrid competitor focused heavily on email APIs.

Its product family includes tools for sending, validating, and optimizing email, making it relevant for developers who need infrastructure rather than a broad customer engagement platform.

For teams comparing SendGrid and Mailgun, considerations are likely to include:

• API and SMTP experience
• Sending volume
• Deliverability tooling
• Email validation
• Analytics
• Routing
• Pricing
• Support
• Infrastructure requirements

This is another relatively direct comparison.

Both are fundamentally email infrastructure choices.

If your primary reason for leaving SendGrid is API experience, pricing, deliverability tooling, or another email-specific requirement, Mailgun belongs on your shortlist.

If you're leaving because your messaging strategy has expanded beyond email, changing email APIs won't solve the underlying problem.

Choose Mailgun if: You want developer-focused email infrastructure.

Consider another option if: You need customer journey orchestration across email and non-email channels.

Best for: Large organizations looking for sophisticated cross-channel customer engagement.

Braze sits in a very different category from a pure email API.

Its platform is designed for customer engagement across channels, including email, push, in-app messaging, SMS, and other customer touchpoints, with segmentation, personalization, journey orchestration, experimentation, and data capabilities surrounding them.

That makes Braze relevant when your SendGrid evaluation isn't really about replacing an email API.

It's about replacing an email-centric approach to customer engagement.

SendGrid is fundamentally an email platform.

Braze is a broader customer engagement platform.

That also means you're comparing very different levels of implementation, functionality, organizational complexity, and potentially cost.

Choose Braze if: You're a large organization looking for enterprise-grade cross-channel customer engagement and have the resources to support a sophisticated platform.

Consider another option if: You primarily need email infrastructure or want a more approachable cross-channel lifecycle platform.

Best for: Teams where mobile messaging and push notifications are central to the customer experience.

OneSignal approaches the market from a different direction than SendGrid.

Its platform supports mobile and web push notifications alongside in-app messaging, email, SMS/RCS, and Journeys.

That makes it particularly relevant for mobile-first products where email is only one component of customer communication.

The easiest way to understand the difference is to look at each platform's center of gravity.

SendGrid centers on email. OneSignal centers much more heavily on push and mobile engagement.

A mobile product sending push notifications for activity, reminders, updates, and promotions may find OneSignal's channel mix more naturally aligned with its needs.

A company primarily sending high-volume transactional email may not.

Choose OneSignal if: Push notifications and mobile engagement are central to your messaging strategy.

Consider another option if: Your requirements revolve primarily around email infrastructure or deeper customer-data-driven lifecycle orchestration.

Best for: Engineering teams building multi-channel notifications directly into their products.

Courier is another case where "SendGrid alternative" doesn't quite capture the architectural difference.

Courier provides a notification infrastructure that developers can use to build messaging across channels and providers.

That includes capabilities around:

• Email
• Push
• SMS
• In-app notifications
• Chat integrations
• Notification routing
• User preferences
• Templates
• Automations

In other words, Courier can operate as an orchestration layer above individual delivery providers.

With SendGrid, your application might essentially say:

Send this email.

With notification infrastructure, the instruction can become:

Send this notification according to this user's preferences and our routing logic.

Those are different jobs.

Choose Courier if: Your engineering team is building a product notification system spanning channels and delivery providers.

Consider another option if: Your primary goal is giving marketing and growth teams control over behavioral lifecycle journeys.

The fastest way to narrow the list is to identify what you actually want to replace.

If you're happy with an email-only architecture and primarily need to replace SendGrid's transactional sending capabilities, Postmark is one of the most direct alternatives.

Evaluate the platforms based on API experience, SMTP, templates, deliverability, analytics, support, and pricing rather than channel count.

Resend and Mailgun both deserve consideration for developer-centric email infrastructure.

Resend emphasizes a modern developer experience, while Mailgun offers mature API-driven email infrastructure and tooling.

The better fit depends on the complexity and scale of your email program.

If you're using SendGrid for marketing email but want more sophisticated behavior-driven lifecycle journeys, Customer.io is a stronger fit.

The difference is especially noticeable when a journey depends on product behavior.

Rather than simply asking whether someone belongs to a contact list, you can build messaging around what they've actually done and what happens next.

For a practical look at this shift, Customer.io's recent data-driven marketing strategies for 2026 explores how behavioral signals can be turned into customer journeys.

If you're searching for a SendGrid alternative specifically because you need push notifications, you're already comparing a different category of platform.

OneSignal is particularly relevant for mobile- and push-centric strategies.

Customer.io is a strong fit when push needs to operate alongside customer data, behavioral segmentation, email, in-app messaging, and lifecycle automation.

Customer.io is a strong option when in-app messaging needs to respond to the same behavioral data powering the rest of your customer journey.

That lets you coordinate the experience instead of treating an in-app message as an isolated campaign.

The opportunity is significant: Customer.io's 2026 research found 3–4x year-over-year growth in in-app message volume, making it the fastest-growing channel in the platform data included in the report.

For large enterprises looking for extensive cross-channel customer engagement capabilities, Braze belongs on the shortlist.

Just recognize that you're making a much broader platform decision than switching email providers.

If developers need to build notification routing, user preferences, and multi-channel delivery into your product, Courier solves a more relevant problem than a conventional email service.

Here's where comparisons of SendGrid alternatives often go wrong.

A list might compare seven products as though they're seven different versions of the same thing.

They're not.

Most options fall into one of three categories.

Examples: SendGrid, Resend, Postmark, Mailgun

The primary job is sending email reliably and at scale.

You'll likely care about:

• Email APIs
• SMTP
• Deliverability
• IP management
• Authentication
• Templates
• Webhooks
• Analytics
• Bounce and suppression handling

If email is the problem, stay in this category.

A broader platform isn't automatically better.

Example: Courier

The primary job is helping developers build notifications into their product.

You'll likely care about:

• Notification APIs
• Channel routing
• Provider abstraction
• User preferences
• In-app notifications
• Multi-channel delivery
• Templates
• Developer workflows

This category makes sense when notifications are part of the product itself.

Examples: Customer.io, Braze, OneSignal

The job expands from delivering individual messages to orchestrating customer experiences.

You'll likely care about:

• Customer profiles
• Behavioral data
• Segmentation
• Journey automation
• Personalization
• Experimentation
• Email
• Push
• In-app
• SMS
• Other customer channels

Email remains foundational, but teams increasingly operate across in-app, SMS, push, and other channels while prioritizing personalization and better data integration.

That's why choosing a SendGrid alternative includes deciding which layer of your messaging stack you need your next platform to own.

Before building your shortlist, answer these five questions.

This is the most important question.

If the answer is:

"We want a different email API."

Compare Resend, Postmark, and Mailgun.

If it's:

"We need push and in-app messaging."

Start evaluating Customer.io, OneSignal, or Braze.

If it's:

"We're building a notification system into our product."

Look at Courier.

Knowing the problem prevents you from comparing products that solve completely different jobs.

Don't buy software based entirely on a hypothetical five-year roadmap.

But don't ignore what you already know is coming, either.

If mobile push is on next quarter's roadmap and you're currently replacing your email platform, it's worth considering whether you want another standalone provider when that channel launches.

Consider the people operating the platform.

Do developers want direct API control?

Do marketers need a visual journey builder?

Does product need in-app messaging?

Does your lifecycle team need to create segments and experiments without engineering support?

Your organizational requirements can eliminate options surprisingly quickly.

There is a big difference between knowing:

This person is on our customer list.

and knowing:

This person signed up three days ago, invited two teammates, hasn't completed setup, viewed the billing page twice, and used Feature A this morning.

The more your messaging depends on the second type of information, the more important event data, segmentation, and journey logic become.

Customer.io's 2026 research found behavioral triggers were one of the top-performing personalization tactics reported by marketers. For more tactical ideas, our customer messaging playbook translates seven of the report's trends into experiments teams can actually try.

If email remains important, don't let a feature comparison distract you from the fundamentals.

Ask potential providers about:

• Authentication
• IP options
• Sender reputation tooling
• Suppression management
• Deliverability monitoring
• Expert support
• Data portability
• Sending-volume requirements

And remember that your own practices matter too.

A new provider can't compensate indefinitely for poor list hygiene, irrelevant messages, weak authentication, or high complaint rates.

If deliverability is a major reason you're evaluating SendGrid alternatives, use our email deliverability guide as a checklist for your evaluation.

The best SendGrid alternative depends on what you need. Postmark, Resend, and Mailgun are strong options for email infrastructure. Customer.io is a strong choice for teams that want transactional and lifecycle messaging across email, push, in-app, SMS, and other channels. OneSignal is particularly relevant for push-heavy mobile engagement.

Several SendGrid competitors offer free tiers or trials, but pricing and plan limits change frequently. Compare current pricing based on your expected sending volume, channels, contacts, and required features, rather than choosing solely because a free plan is available.

Postmark, Resend, and Mailgun are among the strongest SendGrid alternatives when transactional email is your primary requirement. The best choice depends on your sending volume, API and SMTP requirements, deliverability needs, developer preferences, and pricing.

Customer.io is a strong SendGrid alternative when you want email marketing connected to behavioral customer data and lifecycle automation. If you only need conventional email campaigns rather than behavior-triggered customer journeys, a more email-focused platform may be sufficient.

Yes, but Customer.io and SendGrid solve different scopes of the messaging problem. SendGrid primarily provides email infrastructure for transactional and marketing emails. Customer.io combines email with behavioral customer data, journey automation, segmentation, push notifications, in-app messaging, SMS, WhatsApp, and other messaging capabilities.

SendGrid itself is an email product and does not provide native mobile push messaging. Twilio offers other communication products outside SendGrid. If you want email and push within the same customer engagement platform, alternatives include Customer.io, OneSignal, and Braze.

SendGrid itself focuses on email rather than native in-app messaging. Customer.io, Braze, OneSignal, and notification platforms like Courier offer different forms of in-app messaging. The right option depends on whether you're building lifecycle campaigns or product notification experiences.

Customer.io can replace SendGrid for many email and customer messaging use cases, including transactional email and lifecycle campaigns, but the products aren't identical. Teams relying on specific SendGrid infrastructure capabilities should evaluate their technical requirements before migrating. Customer.io becomes particularly compelling when the goal is to consolidate email with behavioral automation and additional channels.

No. SendGrid supports both transactional and marketing email. Its Email API handles programmatic sending, while Marketing Campaigns provides tools for marketing email. However, SendGrid itself remains email-focused even though its parent company, Twilio, offers additional communication products.

SendGrid is built to send email on an enormous scale.

If that's the problem you need to solve, your best alternative may be another email infrastructure provider.

Compare Resend, Postmark, and Mailgun. Look closely at APIs, SMTP, deliverability, analytics, support, and pricing. Pick the infrastructure that works best for your team.

But if you're researching SendGrid alternatives because email no longer represents your entire customer experience, don't stop at comparing email APIs.

Ask a bigger question:

What should own customer messaging in our stack?

Email infrastructure helps you deliver an email.

Notification infrastructure helps developers build notifications into a product.

A customer engagement platform helps you use customer data and behavior to determine who should receive which message, when, and through which channel.

For many growing messaging programs, that third problem eventually becomes the more important one.

And the shift is already happening. Customer.io's latest research found that while email remains ubiquitous, teams are also using in-app, SMS, push, and other channels, while personalization and data integration rank among their biggest priorities for the year ahead.

If you're ready to move from sending emails to orchestrating customer experiences, see what you can build with Customer.io.