While developing a mobile or a web based application, transactional and marketing emails both are equally important from the communication perspective. There are various events in which users of the app need to be communicated with important information using emails. It is impossible to manually manage these sending whenever a specific event occurs. Here, the email APIs come into picture. Email APIs are a service which enables the mobile app development companies to programmatically send the emails to the users of the applications to convey important information relevant to the app. Various scenarios and events such as:
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Forgot Password
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Reset Password
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Transaction and Payment alert emails
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Car is booked email
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Invoice is generated email
and many more are taken care by these email APIs. You might have a questions as to who provides these services? These are the email API service providers who work on subscription model to provide the email APIs for executing such transactional and marketing emails on occurrence of various events in the app’s eco-system. We looked at some of the email marketing tools to use in 2025. Some of those tools offer such APIs to be integrated as well while others in this list are purely providers of the email APIs.
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Top 10 email API service providers of 2025
Some of the leading email API service providers of 2025 include Mailgun, Postmark, Amazon SES, SendGrid, Mandrill, Brevo, Klaviyo, SMTPMart, Mailjet, and Elastic Email. These providers are rich in the email APIs which make the implementation of email module a cakewalk in the applications. Let’s look each of these in detail.
Mailgun
Founded by Ev Kontsevoy and Taylor Wakefield in 2010, Mailgun** is a cloud-based email API service designed for developers to send, receive, and track transactional and marketing emails. It’s widely used for transactional emails like password resets, receipts, and notifications. It offers email parsing capabilities that allow developers to extract structured data from incoming emails. This is something not commonly found in other providers.
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- Pricing:** Free plan - 100 emails/day. Paid plan - starts from $15/month.
- **Ease of integration:** Well-documented API, supports multiple SDKs.
- **Security & compliance:** GDPR, SOC 2, supports DKIM/SPF.
- **Analytics:** Advanced analytics with logs and reports.
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Postmark
Postmark** was founded by Chris Nagele in 2010 under the company Wildbit, later acquired by ActiveCampaign. Postmark is a highly reliable email API provider focused purely on transactional emails. It is a preferred choice for businesses that need instant email notifications as it guarantees quick email delivery. Unlike most providers that mix transactional and marketing emails, Postmark completely separates the two, ensuring optimal deliverability for transactional emails.
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- Pricing:** No free plan. Paid plan - starts from $15/month.
- **Ease of integration:** Simple API, SMTP support.
- **Security & compliance:** SOC 2, GDPR, HIPAA compliant.
- **Analytics:** Real-time open tracking, delivery reports.
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Amazon SES
This provider perhaps doesn’t require an introduction but, the list cannot be complete without it. Amazon SES** was launched by Amazon Web Services (AWS) in 2011. It is a cost-effective and scalable email-sending service provided by AWS. It is best suited for businesses that need to send high volumes of emails, whether transactional or marketing. It integrates seamlessly with other AWS services like Lambda, SNS, and CloudWatch and provides Amazon’s security assurance.
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- Pricing:** Pay-as-you-go model.
- **Ease of integration:** Requires AWS expertise, complex setup.
- **Security & compliance:** Supports DKIM, SPF, ISO certified.
- **Analytics:** Basic tracking, but integrates with AWS CloudWatch.
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SendGrid
Acquired by Twilio in 2018, SendGrid** was founded by Isaac Saldana, Jose Lopez, and Tim Jenkins in 2009. SendGrid offers email warm-up tools to gradually build sender reputation, ensuring better deliverability rates over time. It provides email APIs, SMTP relay, and email marketing tools. It is one of the most popular email platforms used by both startups and enterprises.
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- Pricing:** Free plan - 100 emails/day. Paid plan - starts from $19.95/month.
- **Ease of integration:** Rich API, SMTP support, SDKs.
- **Security & compliance:** GDPR, supports authentication protocols.
- **Analytics:** Advanced reporting with heatmaps and click tracking.
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Mandrill (by MailChimp)
Founded by Ben Chestnut and Mark Armstrong in 2001 and acquired by MailChimp, Mandrill** is a widely recognized email marketing platform that also provides an API for developers to integrate email marketing into their applications. It is best known for its drag-and-drop email campaign builder. It’s deep integration with Mailchimp makes it ideal for users who need both transactional and marketing emails under one platform.
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- Pricing:** Custom plan based on blocks and emails to be sent.
- **Ease of integration:** API with Zapier and CRM integrations.
- **Security & compliance:** GDPR, DKIM, SOC 2, PCI DSS.
- **Analytics:** Rich analytics, conversion tracking.
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Brevo
Formerly known as Sendinblue, founded in 2012 by Armand Thiberge, Brevo** is an email marketing and automation platform offering transactional and marketing email capabilities. It also includes SMS and WhatsApp marketing features. It provides a built-in CRM alongside email and SMS marketing features, making it an all-in-one marketing platform.
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- Pricing:** Free plan - 300 emails/day. Paid plan - starts from $8/month.
- **Ease of integration:** REST API, SMTP relay, WordPress plugin.
- **Security & compliance:** GDPR, SOC 2 certified.
- **Analytics:** Real-time reporting with campaign insights.
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Klaviyo
Klaviyo** is a data-driven email marketing automation platform, primarily used by eCommerce brands for customer segmentation and personalized campaigns. It integrates deeply with Shopify and other eCommerce platforms, providing AI-powered product recommendations for email marketing. It was founded by Andrew Bialecki and Ed Hallen in 2012.
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- Pricing:** Free plan - 500 emails/day. Paid plan - starts from $45/month.
- **Ease of integration:** Deep Shopify & e-commerce integrations.
- **Security & compliance:** GDPR compliant, SOC 2 certification.
- **Analytics:** Behavioral analytics, revenue tracking.
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SMTPMart
SMTPMart** is a community driven email API provider and operates as an independent email delivery platform. SMTPMart is a bulk email delivery service that offers SMTP relay and APIs for sending emails. It is mainly used by small businesses for email marketing campaigns. Due to it’s affordability, it makes a good choice for small businesses that need a budget-friendly email solution.
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- Pricing:** No free plan. Paid plan - starts from $43/month.
- **Ease of integration:** Basic SMTP integration, limited API support.
- **Security & compliance:** SPF, DKIM support but lacks major certifications.
- **Analytics:** Basic reporting, open/click tracking.
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Mailjet
Mailjet** was founded in 2010 by Julien Tartarin and Wilfried Durand and later acquired by Snich. Mailjet is a cloud-based email solution that offers APIs for sending transactional and marketing emails. It is particularly popular in Europe due to its strong GDPR compliance. Allows real-time team collaboration on email templates, similar to how Google Docs works for documents. This not only makes Mailjet a leading choice for API integration but, as an email marketing software to be used by the marketers.
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- Pricing:** Free plan - 200 emails/day. Paid plan - starts from $17/month.
- **Ease of integration:** Easy-to-use API, SMTP relay support.
- **Security & compliance:** GDPR, ISO 27001 certified.
- **Analytics:** Basic analytics, integrates with BI tools.
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Elastic Email
A polish email API provider was founded in 2010 has made it to be list because of it’s distinctive feature of offering unlimited contacts on all plans, making it great for businesses that need to store and manage large email lists.
- Pricing:** Free plan available. Paid plan - starts from $19/month.
- **Ease of integration:** Supports multiple programming languages.
- **Security & compliance:** TLS encryption, GDPR-compliant, 2FA support, DKIM, DMARC, SPF.
- **Analytics:** Comprehensive dashboard with detailed reports on opens, clicks, and bounces.
Conclusion
Email API providers are many and many sprout each day. The real deal lies in selecting what is the best email API provider for your business and app. Based on the parameters other than the ones mentioned above, one should select the best email API service provider. This is something that will stick to your app for a long and is not advisable to change frequently as it is a tedious task. If you are in any doubts, consider connecting with a top mobile app development company who can analyse your requirements, business model, frequency of emails to be sent, and other factors to suggest the best. Each provider mentioned above are good and that is why they have made it to the list. The question lies in what are your needs?