Major Evolution of Meruhaikun: A New Era of Email Marketing SaaS Begins

In the landscape of email marketing, few services can boast the longevity and reliability of Meruhaikun, operated by Delightful Inc., based in Koto, Tokyo. Since its inception in 2002, this pioneering email delivery SaaS has set benchmarks in the industry and is now embarking on a significant evolution. In April 2026, they introduced the new Pro Plan, designed explicitly for lead acquisition and nurturing, expanding its functionalities to cater to the contemporary needs of businesses.

Background of Development: A Shift from Mass Sending to Individual Optimization

Recognized with the ITreview Grid Award 2025 Fall, Meruhaikun has consistently received high accolades from its users over the years. This reputation is underpinned by their swift adaptations to recent changes in Gmail guidelines and the inclusion of DKIM for reliable delivery rates. Today, both B2B and B2C companies face the challenge of converting acquired leads into customers efficiently. Meruhaikun aims to address this need with its newly developed Pro Plan, combining a stable operational foundation with advanced marketing automation features, all starting at an industry-low price of 4,800 yen per month.

Five Key Advancements in the Pro Plan

1. Unlimited Step Emails and Birthday Email Scenarios: Users can create unlimited scenarios and steps that allow personalized communications tailored to the attributes and actions of customers, enhancing conversion rates automatically.
2. Customizable High-Function Forms: Offering over 30 types of customizable forms for various uses, dari exhibitions to seminar registrations. This feature ensures efficient lead information collection through multiple channels that link directly to the database.
3. Retargeting Emails for Effective Follow-ups: By allowing the sending of follow-up emails only to users who have shown interest (like those who opened or clicked), users can secure business opportunities effectively by engaging with leads while their interest is high.
4. Integration with External Systems: The Pro Plan allows seamless integration with external tools like kintone and WordPress. This feature empowers users to utilize data efficiently without disrupting existing workflows.
5. Secure Multi-Administrator Logins: This feature enables multiple users to log in with personal IDs, ensuring proper management of operation logs and maintaining security standards for safe organizational use.

Service Overview and Pricing

The Pro Plan starts with a minimum of 3,000 contacts for 4,800 yen monthly, offering unlimited step emails, form creation, and external integration. Additionally, the Standard Plan serves clients needing up to 7,000 contacts for 3,500 yen monthly, featuring an HTML editor and optional SMS delivery. Both plans ensure high delivery rates adhering to Gmail's guidelines and standard DKIM authentication.

Future Roadmap: Accelerating towards Marketing Automation with AI and MCP

Meruhaikun has ambitious plans for future evolution, promising advancements that include automated target selection via AI and developing AI for generating email content and subject lines. They aim to utilize the Model Context Protocol (MCP) for direct engagement through AI agents.

With the mission of "Optimizing Joy and Maximizing It", Meruhaikun envisions a world where businesses of all sizes, from small to large enterprises, can engage in the most sophisticated yet affordable marketing strategies available.