Best email deliverability tools

Enhance email deliverability: The 8+ best email deliverability tools for developers

14 min read

Email is a cornerstone of business communication, essential for sharing crucial information with employees, candidates, clients, partners, and prospects. The volume of emails sent daily, which has now surpassed 300 billion and continues to grow, underscores the vital importance of email deliverability tools. It’s one of the most critical factors for maximizing ROI from your email efforts. 

Today, we’re taking a closer look at email deliverability, including the latest policies impacting it and the best tools for developers to build and maintain effective email capabilities within their applications. By understanding these changes and tools, you can confidently navigate the email landscape, ensuring you have the insights needed to optimize your in-app email capabilities and increase your business’s success. 

Email provider changes impacting email deliverability 

Recent updates from major email service providers have made email deliverability a hot topic. As of February 1, 2024, Google implemented stricter policies, including a hard spam rate threshold, strong authentication requirements, and mandatory one-click unsubscribes for bulk emails. Yahoo has introduced similar measures. These changes curb spam and protect users but pose challenges for businesses relying on bulk email.

These new regulations significantly impact deliverability rates for those not adhering to best practices. However, companies and developers prioritizing compliance and quality in their email strategies can maintain reliable delivery.

Types of email deliverability tools for developers

Understanding the difference between transactional and contextual email sending is crucial for developers integrating and maintaining email functionalities within their applications. Transactional emails, or mass and bulk emails, are automated messages sent to many recipients, such as newsletters and promotions. In contrast, contextual sending involves emails sent directly from users’ go-to email service providers, fostering high-quality, conversational experiences (one-to-one or one-to-few) that recipients are more likely to receive and engage with. 

Why email APIs are the best email deliverability tools for developers

Email APIs are among the best email deliverability tools for developers aiming to optimize deliverability. These APIs enable seamless integration with users’ preferred email services, ensuring high deliverability and engagement by leveraging familiar, trusted platforms. Email APIs support best practices by offering strong authentication protocols and tools for managing unsubscribes, bounces, and engagement metrics, making them indispensable for developers focused on enhancing email deliverability.

What makes a great email deliverability tool?

Several key features and capabilities are essential when choosing an email deliverability tool to ensure your emails consistently reach their intended recipients.

Here are the critical attributes that define a great email deliverability tool and how an email API can help:

  • Spam filter testing: A top-tier tool should provide comprehensive spam filter testing, allowing you to identify and rectify elements that may cause your emails to land in spam. Email APIs can integrate with spam filter testing services to automate this process, ensuring your messages land in the inbox rather than the junk folder.
  • Authentication protocols: Robust support for email authentication protocols like SPF, DKIM, and DMARC is crucial. Email APIs facilitate implementing and managing these protocols, helping verify that your emails are legitimately from you and reducing their chances of being marked as spam.
  • Bounce management: Effective handling of bounced emails, including identifying hard bounces (permanent delivery failures) and soft bounces (temporary issues), helps maintain a clean email list and improves overall deliverability rates. Email APIs can help automate bounce management, providing real-time updates and actionable insights.
  • Detailed analytics: Comprehensive analytics and reporting capabilities enable you to track open rates, click-through rates, bounce rates, and other essential email metrics. Some email APIs offer robust analytics features that integrate seamlessly into your existing systems.
  • Deliverability consulting: Access to expert deliverability consulting can be invaluable. Experts can provide tailored advice and strategies to improve your deliverability rates, ensuring your emails reach more recipients. 
  • Compliance features: Features that help you comply with GDPR, CAN-SPAM, and other email marketing laws are essential. This includes easy-to-use unsubscribe options, consent management, and data protection measures. Email APIs ensure compliance by automating consent management, unsubscribe processes, and data protection protocols.
  • List management tools: Efficient list management tools help you segment your audience, manage subscriptions, and keep your email lists clean and up-to-date, which is vital for maintaining high deliverability rates. Email APIs can provide advanced list management capabilities, allowing easy integration with your existing databases and CRM systems.
  • User-friendly interface: An intuitive and user-friendly interface ensures you can easily navigate the tool, set up campaigns, and access important deliverability data without a steep learning curve. Email APIs often include developer-friendly interfaces and documentation, making integrating and using the tools more efficient.
  • Integration capabilities: Seamless integration with your existing email marketing platforms and CRM systems is crucial for a smooth workflow and comprehensive data synchronization. Great email APIs are designed to integrate effortlessly with your current tech stack, ensuring a smooth and efficient workflow.

By focusing on these features and leveraging the capabilities of email APIs, you can choose an email deliverability tool that enhances your email marketing efforts, ensures your messages reach their audience, and ultimately drives better results for your business.

Developer’s guide to the best email deliverability tools

We’ve compiled a list of the best email deliverability tools available today to help you navigate the latest standards and ensure your emails reach their audience. These tools will optimize your email campaigns and keep you ahead in this ever-evolving landscape, making your job as a developer easier and more efficient.

1. Nylas Email API

Best email deliverability tool Nylas

Best for: Developers building and maintaining in-app contextual email 

The Nylas Email API ensures nearly 100% email deliverability by enabling users to send messages directly from their email addresses rather than a shared domain or IP address. This reduces the risk of emails being marked as spam and increases engagement. Unlike other email APIs, Nylas allows users to send, receive, and manage their entire inbox within your application, with full CRUD capabilities to reduce context switching and increase productivity. It offers a developer-friendly interface and comprehensive documentation, making integration straightforward.

Key features of Nylas for email deliverability:

  • Authentication protocols: Supports hosted authentication with OAuth, API key/access token, custom authentication, and IMAP authentication.
  • Bounce Detection: Accurately detects 95% of email bounces and triggers a webhook every time an email bounces.
  • Detailed analytics: Provides comprehensive analytics to track open rates, click-through rates, bounce rates, and other essential metrics, helping optimize future campaigns.
  • Compliance features: Adheres to the highest security and compliance standards.
  • Integration capabilities: Seamlessly integrates with all major email service providers (Gmail, Outlook, Yahoo, IMAP, etc.) and your existing tech stack, ensuring smooth workflows and data synchronization.
  • Robust developer documentation and resources:  Nylas shares in-depth knowledge on improving email deliverability via documentation and video tutorials.  
  • High uptime: Guarantees 99.9% uptime.

Nylas is the ideal choice for developers seeking a reliable, secure, and comprehensive email API that enhances productivity and ensures exceptional email deliverability.

Pricing: Nylas offers a full-service API platform with an email, calendar, and contacts API. Customers can choose from 3 pricing tiers:

  • Free: Developers can connect up to 5 accounts to build, test, and iterate.
  • Pay-as-you-go: Available for Full Platform packages. Nylas offers a month-to-month option so you can build on your own schedule.
  • Custom: Available for Full Platform or Calendar-only packages. Nylas’s custom plans allow customers to choose a plan that suits their needs, ensuring they only pay for their desired features and capabilities.

Talk to an expert to choose the best plan for your team.

2. Twilio SendGrid Email API 

Email deliverability tool_Sendgrid

Best for: Developers building transactional email capabilities 

SendGrid offers developers a transactional email API to help ensure high deliverability and reliable email performance. While contextual APIs like Nylas connect directly to users’ email accounts for a more conversational email experience, transactional APIs support large-scale outreach beyond rate limits. Many teams use both APIs to deliver a unified experience.

Key features of SendGrid for email deliverability:

  • IP management: Optimized IP setup, automated IP warmup, and dedicated IPs for Pro and higher plans.
  • Authentication protocols: Supports SPF, DKIM, and reverse DNS.
  • Feedback loop management: ISP feedback loop sign-ups to manage complainers.
  • Reputation management: Dashboard with alerts and reporting.
  • Bounce management: Handles bounce management and email validation for Pro and higher plans.
  • Blacklist monitoring: Monitors domain and IP addresses.

Pricing: Free plan includes partial functionality for up to 100 emails per day. The Essentials plan starts at $19.95 per month for 10,000 emails. The Pro plan starts at $89.95 per month. 

3. Mailgun Email API 

Email deliverability tool_Mailgun

Best for: Developers building transactional email capabilities and needing personalized support 

Mailgun provides a transactional email API for sending, receiving, and tracking emails, making it suitable for developers managing high-volume email campaigns. It offers features for maintaining high deliverability rates and detailed analytics to optimize email performance. For developers looking for additional support, Mailgun offers deliverability services for an extra fee.

Key features of Mailgun for email deliverability:

  • Email validation: Removes invalid and high-risk email addresses to reduce bounces.
  • Inbox placement testing: Identifies potential delivery issues before sending emails.
  • Email preview: Previews emails across 100+ devices and clients to spot formatting issues.
  • Reputation monitoring: Integrates with Google Postmaster Tools and Microsoft SNDS for reputation tracking.
  • Blocklist monitoring: Monitors IPs and domains against blocklist providers in real-time.
  • Spam trap monitoring: Tracks sending to known spam traps to protect reputation.

Pricing: Free plan includes partial functionality for up to 100 daily emails. Paid plans start at $15 per month.

4. Postmark Email API 

Email deliverability tool_Postmark

Best for: Developers building transactional email capabilities, fast 

Postmark offers a transactional email API that prioritizes fast and reliable email performance, ensuring high deliverability rates. It helps developers quickly deliver transactional emails, robust authentication protocols, and detailed analytics to monitor and improve email performance.

Key features of Postmark for email deliverability: 

  • Fast delivery: Optimized for quick transactional email delivery.
  • Authentication protocols: Can support SPF, DKIM, and DMARC.
  • Inbound processing: Handles inbound emails and parses content.
  • Detailed analytics: Tracks open rates, delivery times, and engagement metrics.
  • Reputation monitoring: Monitors sender reputation and provides actionable insights.
  • Template management: Offers tools for creating and managing email templates.

Pricing: The free developer plan includes partial functionality for up to 100 emails per day with optional add-ons like dedicated IPs starting at $50 per month per IP and DMARC monitoring starting at $14 per month per domain. 

5. SparkPost 

Email deliverability tool_Sparkpost

Best for: Developers requiring advanced analytics for transactional email 

SparkPost is a cloud-based email service provider offering email delivery solutions. Its cloud-based SMTP service enables companies to send bulk emails with high deliverability rates. Additionally, SparkPost offers an API platform that allows developers to build custom applications for sending and tracking emails.

Key features of SparkPost for email deliverability:

  • High throughput: Efficiently handles large volumes of emails.
  • Advanced analytics: Performs predictive and real-time analytics to prevent email delivery problems, providing detailed insights into email performance, including open rates, click-through rates, and engagement metrics.
  • Reputation monitoring: Monitors sender reputation and provides actionable insights.
  • Authentication protocols: Supports SPF, DKIM, and DMARC to prevent spoofing and phishing.
  • Template management: Tools for creating and managing email templates.
  • Recipient engagement tracking: Tracks recipient interactions to optimize future campaigns.

Pricing: 

  • Starter plan: Starts at $20 per month for up to 50,000 emails.
  • Premier plan: Custom pricing based on email volume and additional features.

6. Amazon SES (Simple Email Service)

Best for: Developers needing a cost-effective email solution for transactional sending 

Amazon Simple Email Service (SES) is a cloud-based email service designed to help developers send and receive emails from any application. It simplifies the process of sending large volumes of emails, offering a variety of integration methods and robust deliverability features.

Key features of Amazon SES for email deliverability:

  • Flexible sending options: Use the Amazon SES console, SMTP interface, or SES API.
  • Deliverability tools: The Virtual Deliverability Manager provides insights, recommendations, and automatic improvements for email deliverability.
  • Reputation monitoring: Tools to monitor and maintain sender reputation.
  • Authentication protocols: Supports SPF, DKIM, and DMARC.
  • Customizable IP Options: Shared IPs, dedicated IPs, and Bring Your Own IP (BYOIP) options.
  • Detailed analytics: Track sending statistics, including delivery, open rates, clicks, bounces, and complaints.
  • Mailbox simulator: Test email handling scenarios without affecting sender reputation.

Pricing: Amazon SES offers a flexible free tier with up to 3,000 message charges per month for the first 12 months. After that, it charges $0.10 per 1,000 emails sent or received. Additional costs include $0.12 per GB for attachments, $24.95 per month for dedicated IP addresses, and $1,250 for the Deliverability Dashboard. 

7. Netcore Email API 

Good for: Developers needing a cost-effective email solution for transactional sending 

Netcore Email API, previously known as Pepipost, is a cloud-based email delivery service designed to help businesses send notifications, newsletters, updates, and other transactional emails. The platform supports SMTP and HTTP API integration options, providing flexibility for different technical needs.

Key features of Netcore for email deliverability:

  • Email delivery: Utilizes intelligent algorithms to optimize sending patterns for improved deliverability.
  • API integration: Supports multiple programming languages, facilitating easy integration via SMTP or HTTP API.
  • Security: Implements SSL encryption, DKIM, SPF, and DMARC authentication protocols.
  • Analytics: Offers real-time monitoring and detailed analytics to track email performance.
  • Dedicated IPs: Provides options for dedicated IPs to enhance sender reputation for high-volume senders.
  • Webhooks: Delivers immediate feedback on email delivery status.
  • Real-time reporting: Detailed dashboards offering insights such as deliverability health scores and inbox placement.

Pricing: Netcore offers a free plan for up to 25,000 monthly emails. Paid plans start at $25 per month for up to 150,000 emails, with scalable options for up to 2,000,000 emails at $445 monthly.

8. Mailjet

Good for: Marketers needing a transactional email solution with collaboration features

While Mailjet offers an email API that supports both transactional emails, it’s known for its email builder and marketing features. It is suitable for marketers and teams that need effective collaboration tools and reliable email delivery; however, it has limited integrations compared to more developer-focused tools.

Key features of Mailjet for email deliverability:

  • Real-time monitoring: Tracks performance metrics such as open rates, click-through rates, and deliverability.
  • Advanced analytics: Provides insights into email campaigns for optimization.
  • Segmentation and personalization: Tools for segmenting audiences and personalizing emails.
  • SMTP relay and API integration: Integrates with existing systems for sending emails.
  • A/B testing: Allows testing of different email versions to find the most effective one.
  • Compliance: GDPR and ISO27001 certified, ensuring data security and privacy.

Pricing: Mailjet offers a free plan for 6,000 monthly emails (200 emails per day limit). The Basic plan costs $9.65 per month for 30,000 emails, and the Premium plan starts at $20.95 monthly. 

9. Brevo 

Good for: Marketers and small to medium-sized businesses needing an all-in-one email marketing solution

Brevo (formerly Sendinblue) offers an email marketing platform with tools for creating, sending, and analyzing marketing and transactional emails. It is well-suited for marketers needing an integrated email and SMS campaign approach. Additionally, Brevo offers a transactional email API, making it a valuable tool for developers looking to integrate email functionalities into their applications.

Key features of Brevo for email deliverability:

  • SMTP relay and API: This service provides flexible setup options with SMTP relay and a transactional email API that supports multiple programming languages.
  • Advanced analytics: Offers insights into email performance, including open rates, click-through rates, and engagement metrics.
  • Spam testing: Identifies potential issues that might cause emails to be marked as spam.
  • Dedicated IPs: Available for high-volume senders to enhance deliverability.
  • Reputation monitoring: Tools to monitor and maintain sender reputation.

Pricing: Sendinblue offers a free plan for up to 300 daily emails. The Starter plan starts at $15 per month for 20,000 emails. The Business plan starts at $65 per month and includes additional features such as A/B testing and advanced statistics. The Enterprise plan is custom-priced and includes dedicated support and a dedicated IP address. 

Choose the best email deliverability tool 

Selecting the right email deliverability tool is essential for developers looking to optimize their in-app email communications and maintain high engagement rates. While each tool we’ve reviewed has strengths, Nylas stands out as the most comprehensive choice for contextual email. The Nylas Email API helps developers build native email integrations, ensuring nearly 100% email deliverability. It allows users to send messages directly from their email addresses, thus improving and maintaining their sending reputations.

Additionally, Nylas offers a calendar API and a contacts API, making it a versatile platform beyond email deliverability. 

Explore how Nylas can elevate your email strategy and leverage its unique strengths by connecting with an expert and finding the plan that best suits your needs.

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