MailerSend vs. Postmark Comparison Chart

Klaviyo is an all-in-one platform that makes it easy for B2C businesses grow by integrating marketing, analytics, and customer service in one solution. Powered by unified data and built-in AI, it's faster and easier than ever to create personalized, lasting customer relationships. Klaviyo unifies your customer profiles by capturing every event, and then lets you orchestrate your email marketing, SMS marketing, push notifications, WhatsApp, and RCS campaigns in one place. Klaviyo AI helps you build audiences, write copy, and optimize — so you can always send the right message at the right time, automatically. With real-time attribution and insights, you'll be able to make smarter, faster decisions that drive ROI. Trusted by more than 170,000 businesses, Klaviyo can grow your business while keeping operations simple and customer relationships strong.

Send messages your customers want to read (and act on). Attentive’s AI-powered SMS & email platform helps retail enterprises to e-commerce entrepreneurs engage customers and drive billions in revenue. We'll help you target the right audience and measure your most important metrics to optimize your marketing program. And with over 100 flexible integrations, you can seamlessly connect to the rest of your marketing stack. We partner with industry innovators in retail & e-comm, food & beverage, and media & entertainment. Attentive’s AI-powered SMS & email platform will double your ROI in just a few months. Learn more about our free 30-day trial.

We engage with your emails to teach inbox providers not to send your emails to spam. Our clients have seen their open rates more than DOUBLE within 1-2 weeks! Highly engaged recipients not only open emails, but scroll down as they read. So long as the content is longer than the page, this should be done for nearly all opened emails. When a recipient goes out of their way to take an email out of spam, they are telling the inbox provider, hey, you made a mistake. Moving an email from the promotions folder to the primary inbox tells inbox providers that you disagree with their sorting criteria and it and similar emails should go to the primary inbox. Demonstrates that recipient is interested in the content of your email. We have a set of random generic replies we use for this. Marking an email as important can essentially be interpreted by the inbox provider as "This email is extremely valuable, never send it to spam."

HubSpot brings your marketing, sales, and service teams together on the same AI-powered customer platform. HubSpot's Customer Platform is not just a tool; it's the heartbeat of your business. Designed with passion and precision, our CRM stands out as the ultimate solution for empowering your team to build deeper customer relationships. It transforms the way you engage with your clients by offering a seamlessly integrated, all-in-one platform for sales, marketing, and customer service. With HubSpot's CRM, you gain unparalleled insights into your customer interactions, all organized in an intuitive, easy-to-navigate dashboard that promises to skyrocket your team's efficiency. Our platform is engineered to grow with you, offering scalable solutions that adapt to your evolving business needs. What's more, HubSpot's Customer Platform includes a robust free version, packed with essential features, making it the perfect choice for ambitious businesses of all sizes.

Twilio's Messaging API is a powerful tool that enables businesses to integrate messaging capabilities into their applications seamlessly. It offers a stable RESTful API that allows developers to send and receive SMS, MMS, and WhatsApp messages globally. With Twilio's Messaging API, businesses can automate and scale their communications, ensuring messages are delivered over the preferred channels of their customers. The API supports a variety of sender types, including long codes, short codes, toll-free numbers, and alphanumeric sender IDs, providing flexibility in how messages are sent. Additionally, Twilio's Messaging Services feature allows companies to group global senders and enable intelligent sending, automating sender selection, and handling compliance regulations. The API also supports inbound webhooks, allowing businesses to handle responses programmatically and engage in two-way conversations with their customers.

Get a toll-free number and increase your sales globally. Turn your world into your office. 800.com lets you run your business using your cell phone. Advanced calling features, forwarding to cell phones and no contract. Increase conversions, brand recall ability, increased call response and SMS messaging. Have professional greetings, manage extensions and manage your account online. 800.com offers standard forwarding, simultaneous ringing and sequential ringing. For any business in the world to be taken seriously by US consumers a company should be using a Toll Free Number because it is the gold standard of telephone numbers. Local numbers send a signal that your company doesn’t focus on doing business with consumers in the entire country. Every 800.com member gets access to every phone system tool they could ever think of, regardless of which plan they choose. In addition to helping your customers avoid long-distance fees, you will be helping you and your company, too.

Knak is the no-code platform that empowers self-sufficient marketing teams to create beautiful, on-brand emails and landing pages — without relying on developers or agencies. Built for speed and collaboration, Knak streamlines campaign production with modular templates, real-time editing, simple collaboration, and seamless integrations with leading MAPs like Adobe Marketo Engage, Salesforce Marketing Cloud, Oracle Eloqua, and more. Whether you're supporting global teams or launching fast-turn campaigns, Knak helps you go from brief to build in minutes—not weeks. Say goodbye to bottlenecks and hello to marketing agility.

Melissa’s Web APIs provide a comprehensive solution for global data verification, cleansing, and enrichment to maintain reliable data. Verify, standardize and cleanse global identities, addresses, phones & emails, powered by AI-driven reference data. Our flexible APIs are designed for modern interfaces, including REST, JSON, and XML are easily accessible through our Developer Portal, where you can build, test, and explore integrations. Enhance your data with geographic, demographic, and firmographic insights, along with U.S. property data for advanced enrichment. Melissa supports seamless integration with popular platforms such as Salesforce, Shopify, and more, making data management and governance simple and efficient. Whether you’re focused on data management, data validation, or leveraging our APIs into your website or mobile applications, Melissa helps you unlock the full potential of your data. Get started with 1,000 complimentary credits! All you need is a Melissa account

GetResponse provides all-in-one marketing software that empowers marketers, solopreneurs, coaches, creators, and small business owners with affordable, easy-to-use tools for email marketing, marketing automation, and content monetization. With over 25 years of expertise, GetResponse goes beyond email with tools to help grow and engage audiences, create and sell courses, and turn ideas into income. It’s the go-to solution for building a personal brand, selling products and services, and fostering a loyal community.

TextUs is the leading text messaging service provider for businesses that want to engage in real-time conversations with customers, leads, employees and candidates. Text messaging is one of the most engaging ways to communicate with customers, candidates, employees and leads. 1:1, two-way messaging encourages response and engagement. Text messages help teams get 10x the response rate over phone and email. Business text messaging has become a more viable form of communication than traditional mediums. The TextUs user experience is intentionally designed to resemble the familiar SMS inbox, allowing users to easily manage contacts, conversations, and campaigns. Work right from your desktop with the TextUs web app or use the Chrome extension alongside your ATS or CRM. Leverage the mobile app for on-the-go sending and responding.