Compare MailerSend vs. Postmark

Reliable cloud-based email hosting includes features such as spam filtering, antivirus protection, ample storage, and webmail access. It seamlessly integrates with Outlook as well as various other POP3/IMAP clients. For users with high sending needs, it offers a robust SMTP service designed for responsible senders. Additionally, there is an outbound relay service tailored for transactional emails, marketing campaigns, newsletters, and diverse applications. The infrastructure supports dedicated email servers, clustering, and multiple IP load balancing to accommodate high-volume senders effectively. With a fixed monthly fee, users benefit from unlimited sending capabilities and reputation monitoring. Greatmail stands out as an email service provider (ESP) focused on delivering business-class email hosting, SMTP hosting, and specialized email servers. Furthermore, for ISPs, software developers, and cloud architects, we also create custom solutions featuring dedicated IP servers and load-balanced configurations with multiple servers to meet specific processing needs. This commitment to adaptability ensures that all clients receive the best possible service, tailored to their unique requirements.

We work with you to make sure your inbox providers don't send spam emails to your email. In just a matter of weeks, our clients have seen their open rates increase by more than DOUBLE! High-engagement recipients open emails and scroll down as they read. This should be done for almost all emails that are opened, as long as the content is not longer than the page. If a recipient takes an email from spam and goes out of their way, it is telling the inbox provider that they made a mistake. Inbox providers will be able to tell if you move an email from the promotions folder into the primary inbox that you don't agree with their sorting criteria. It and other similar emails should go directly to the primary mailbox. It shows that the recipient is interested in your email content. The inbox provider can interpret this as "This email is extremely important, please do not send it to spam."

Communicate with your customers through messages they find valuable and are motivated to respond to. Attentive offers an advanced SMS and email platform driven by AI, designed to assist businesses ranging from large retailers to budding e-commerce entrepreneurs in enhancing customer engagement and generating substantial revenue. Our services will enable you to accurately target your desired audience and track essential metrics, allowing you to fine-tune your marketing strategies effectively. With more than 100 versatile integrations, you can easily link our platform with your existing marketing tools for a more cohesive experience. We collaborate with cutting-edge leaders across various sectors, including retail and e-commerce, food and beverage, as well as media and entertainment. By utilizing Attentive’s innovative SMS and email solutions, you could potentially see a doubling of your return on investment within just a few months. Explore the benefits of our complimentary 30-day trial today to experience the difference firsthand.

Klaviyo empowers businesses to create smarter digital relationships by transforming customer data into meaningful, impactful experiences. From email and SMS to web interactions and reviews, Klaviyo makes it easy for B2C brands to engage customers at every touchpoint. Trusted by over 157,000 businesses, Klaviyo helps drive faster, more efficient revenue growth. Klaviyo’s 350+ integrations making getting started easy for marketers. Some key features of the platform include predictive analytics, AI automation, optimized templates, A/B testing, and intuitive segmentation and email flows to ensure marketers are reaching their audience with the right message at the right time. The solution also supports integration with payment processing and point of sale (POS) software solutions, such as Magento, Shopify, and WooCommerce.

Twilio's Messaging API is an essential tool for businesses looking to integrate messaging capabilities into their applications with ease. It provides a reliable RESTful API that facilitates the sending and receiving of SMS, MMS, and WhatsApp messages on a global scale. This API allows businesses to automate and scale their communications, ensuring that messages reach customers through their preferred channels. With support for various sender types, such as long codes, short codes, toll-free numbers, and alphanumeric sender IDs, Twilio offers flexibility in message delivery. The Messaging Services feature further enhances this by enabling the grouping of global senders and intelligent sending, which automates sender selection and manages compliance regulations. Additionally, the API supports inbound webhooks, allowing businesses to handle responses programmatically and engage in two-way conversations with customers. Twilio's comprehensive documentation, sandbox testing, and robust support empower businesses to create efficient, scalable, and compliant messaging solutions that enhance customer engagement and drive conversions.

Knak is the enterprise-grade, no-code solution that transforms how marketing teams build emails and landing pages — without relying on developers or agencies. With a robust modular design system, real-time collaboration, and native integrations with platforms like Marketo, SFMC, and Eloqua, Knak eliminates production bottlenecks while preserving brand governance. Empower your team to deliver high-performance assets quickly, securely, and at scale — no code required. Trusted by global brands to streamline campaign execution and accelerate time-to-market.

GetResponse offers an all-in-one marketing platform designed to equip marketers, solopreneurs, creators, coaches, and small business owners with powerful, user-friendly tools for email marketing, automation, and content monetization. With more than 25 years of experience, GetResponse supports audience growth and engagement through email campaigns, enables seamless course creation and sales, and helps turn passion into profit. It’s the ideal choice for building personal brands, selling products and services, and creating loyal customer communities.

EasyDMARC is a cloud-based DMARC solution for securing domains and email infrastructure, protecting organizations against phishing attacks, and more: Brand Protection Our email protection SaaS platform stops hackers from sending phishing emails to customers from company names, gaining access to accounts, and stealing personal information. Increased Email Deliverability EasyDMARC informs receiving mail servers that emails are legitimate and authentic, ensuring they’re delivered to the inbox instead of blocked or sent to spam. Visibility Into Cyber Threats EasyDMARC helps to successfully monitor every aspect of your email authentication and enforce effective protection from phishing attacks thanks to its advanced reporting capability. Business Email Compromise (BEC) Protection Most people have seen emails pretending to be from the CEO, CFO, or another executive in their organization. EasyDMARC prevents business email compromise and keeps your company reputation on the highest level․ EasyDMARC’s deliverability tool, EasySender, covers all the aspects of email deliverability. The variety of features on the platform cover email list verification, mailbox warmup, and inbox placement.

Elevate your business communications with Notifyre's secure SMS and fax solutions. Streamline SMS and faxing processes online, via email, app, or effortlessly integrate through our developer-friendly SMS and fax API. We're ISO 27001 certified and fully HIPAA compliant, giving you the utmost security for your faxes and SMS messages. Notifyre users from flexible pay-as-you-go fax & SMS and outstanding value receive fax plans and 10DLC number plans. 5 Star service guarantee! -Fax Online, Email to Fax, Fax API - Receive Fax Online -> Encrypted Cloud Storage -Online Fax Numbers -Fax Number Porting -Fax Broadcast 40,000+ Utilise the power of SMS messaging in your business, engaging with your audiences via SMS. Send SMS broadcasts or bulk SMS for marketing, promotions, surveys, support, alerts, or notifications all via a user-friendly secure online SMS portal. - 10DLC Virtual SMS Numbers -> Book a Demo for one-on-one guidance! - SMS Online, Email to SMS, SMS API - Mass Text Message Broadcast + SMS Marketing - Subscriber Management - Contact Management, Bulk Upload + Merge Fields + SMS Templates - Appointment Reminders, eCommerce Promo & Cart Reminders, SMS Alerts & Notification & More

CallHub is a digital organizing platform built for political campaigns, nonprofits, advocacy groups, unions, and businesses to scale their outreach through calling, texting, email, and workflow automation. The platform includes Predictive, Power, and Auto Dialers for efficient and personalized calling. Its AI-powered Smart Insights analyze call sentiment, while Dynamic Caller ID, Spam Shield, and SHAKEN/STIR compliance ensure higher connection and answer rates. CallHub’s texting tools, Peer-to-Peer Texting, Text Broadcasts, and Text-to-Join support SMS/MMS, URL tracking, and automated replies. Workflow automation enables coordinated multi-channel campaigns, and the mobile app empowers volunteers to participate from anywhere. With native integrations for NationBuilder, NGP VAN, Salesforce, and Blackbaud, CallHub ensures seamless data sync across CRMs. The platform is SOC 2, ISO 27001, GDPR, and TCPA compliant. Trusted by over 200,000 campaigns worldwide, CallHub has powered 1 billion calls and 750 million texts, helping organizations connect, mobilize, and win.