Best SMTP Services

Critical Impact allows you to enhance and simplify your email marketing campaigns. Our tools let you effectively manage your email and SMS lists, send personalized and automated emails, along with text messages (SMS) for your marketing campaigns all at a competitive price model. Our subscriber scoring algorithms will mine your data to quickly identify those subscribers who are most likely to read your next email, consume additional emails, or make another purchase. With our easy-to-use interface, you can schedule messages to send in minutes. Select your send options all on one page, and then prevent mistakes by seeing a confirmation of all your send details. Even A/B test your email across device screens – from phones to tablets to monitors.

Reliable SMTP relay and email delivery services. Powerful email delivery services that enable you to send and track high volume emails effortlessly. Integrate and start sending in minutes. All your transactional, email relay and email delivery needs under one roof. Whether you need a low-latency email delivery provider for your transactional emails, scalable infrastructure for high-volume sends or reliable backend solution for your marketing campaigns, SMTP is built to deliver. Reputation Defender is SMTP’s proprietary technology that uses big data to proactively monitor your email list health and safeguard your domain and IP reputation among ISPs by suppressing bad emails in your sends from hard and soft bounces. This ensures your delivery rates and inbox placement incrementally gets better over time.

Say hello to Brevo (formerly Sendinblue) — the platform that helps you build customer relationships across Email, SMS, Chat, and more. The complete toolkit to turn one-time browsers into long-term customers. Connect with contacts directly in their inbox with beautifully designed email campaigns. Send targeted messages that land straight in your customers' pockets. Brevo empowers businesses to build and grow relationships through marketing automation, email campaigns, transactional emails and SMS messages. What makes us different? Brevo is powered by our world-class customer happiness team and we offer pricing plans guaranteed to make you smile. Our platform combines a robust suite of services within a single, user-friendly solution. Happy Sending!

Email is the backbone of your customer engagement. The Twilio SendGrid Email API is the email service trusted by developers and marketers for time-savings, scalability, and delivery expertise. Our flexible Email API and proprietary Mail Transfer Agent (MTA), intuitive console, powerful features, and email experts make it easy to ensure all your email gets delivered in seconds and without interruption. Monitor engagement data and optimize deliverability with our Deliverability Insights dashboard. Whether you’re sending 100 emails or 100 billion, SendGrid is built to scale. Integrate with our RESTful APIs and SMTP in minutes, with sample code libraries available in 7 languages, interactive docs, templates, and more.

The email solution for fast-moving teams. We know how hard it can be to find an affordable and effective email service. Mailjet is the perfect solution for your needs, our advanced features help you grow your business at a very reasonable price. Effortlessly craft beautifully responsive email in just a few clicks with our email editor, Passport. Use our rich library of free email templates or create your own design from scratch. Use Mailjet’s Collaboration Toolkit to work on the same email template or campaign in real time to increase your team’s efficiency. Drastically shorten feedback cycle with commenting and approval workflow features to go faster. Personalize each email with customer data you collect and segment your contact list to send the right content to the right customer. It’s easy to make each of your recipients feel special. Optimize the performance of your campaign with real-time statistics available with each sending.

KingSMTP.com (formerly known as Kingmailer.co, founded in 2017) is a Transactional SMTP service provider. It’s designed to help businesses reliably send emails such as order confirmations, password resets, or notifications, but it’s not intended for mass email campaigns or marketing.

Amazon Simple Email Service (SES) is a cost-effective, flexible, and scalable email service that enables developers to send mail from within any application. You can configure Amazon SES quickly to support several email use cases, including transactional, marketing, or mass email communications. Amazon SES's flexible IP deployment and email authentication options help drive higher deliverability and protect sender reputation, while sending analytics measure the impact of each email. With Amazon SES, you can send email securely, globally, and at scale. Using either the Amazon SES console, APIs, or SMTP, you can configure email sending in minutes. Amazon SES also supports email receiving, enabling you to interact with your customers at scale. Regardless of use case or sending volume, you only pay for what you use with Amazon SES.

MailerSend is a transactional email and SMS service designed for developers to work faster and smarter. A drag & drop builder and dynamic templates enable anyone at any skill level to create personalized transactional emails, while our SMS templates help you create professional transactional SMS messages. MailerSend’s advanced infrastructure scales with your sendings, while the latest security protocols protect your sender reputation. Plus, you can integrate your email sending and tracking in your apps using SMTP or a flexible email API. Built by deliverability experts, and with the inbuilt email verification tool, you can rest easy knowing your messages will be delivered and avoid spam folders, while dedicated IPs are available for high-volume senders. Plus, inbound routing enables your customers to interact with your messages, sparking conversations and increasing engagement. Get started for FREE with 500 emails, then upgrade for as little as $7/month for up to 5000 emails.

-- The email engine you can build on -- We're everything that happens under the hood of your email communications. Reliable Email API with endless capabilities & features ready for integration. Flowmailer's Email Engine provides all the tools you need to build a professional email strategy. From marketing to customer support, from account management to warehousing, every email sent is valuable. Where others choose to focus on an email's looks rather than its performance - we opt for solid email deliverability first. Every email that hits the inbox is a valuable moment between you and your customer. Email Engines change the way we send emails. Ready to create the unparalleled email experience your customers deserve?

Transactional emails: Reach inboxes when it matters most. Deliver fast, personalized transactional emails using API or SMTP. Get the benefits of our experience sending billions of emails globally. Send personalized transactional emails that reach inboxes, not spam folders. Customize your analytics with pre-built dashboards, export API, and more. Read documentation guides, or contact our award-winning Support team for help. Use custom tagging, whitelabeling, conditional content, and more. Globally distributed infrastructure: Featuring automatic SPAM loop registration and pre-warmed dedicated IPs. Get analytics in multiple ways, plus custom tags, A/B test capabilities, and comparative reports. Utilize white-labelled click tracking, custom reverse DNS, rules engine, custom return path, and sub-accounts. That’s the average time to delivery for top 3 ISPs, sent from our MTAs to the recipient’s email server.