Coremail serves as a comprehensive enterprise email solution that forms the backbone of a company’s communication system—enhancing daily productivity and giving IT teams full administrative control. First launched in 1999 by Guangdong Yingshi (Mailtech) in China, Coremail today powers email for 20,000+ organizations worldwide across government, education, financial services, and large enterprises (including Fortune 500 companies in Asia). The platform scales effortlessly to support hundreds of millions of users, focusing on security, reliability, AI enablement, and customizability.
Coremail provides the core infrastructure for enterprise email operations, enabling organizations to send, receive, store, and manage emails and user accounts efficiently.
In essence, Coremail functions similarly to platforms like Microsoft Exchange or other enterprise mail servers, but it stands out with its enhanced security, proven reliability, and advanced features that meet the needs of today’s modern businesses.
Coremail offers a comprehensive suite of products and services designed to manage the entire email lifecycle within one system:
- Enterprise Mail Server
- Email Hosting Services
- Email Archiving
- Email Security Gateway
- Email Data Leakage Prevention (DLP)
Collectively, they give businesses the ability to control and protect every aspect of their email operations — all in one place.
What Makes Coremail Stand Out for Modern Enterprises
Coremail comes with a wide range of powerful features designed to meet the communication and security needs of modern organizations, empowering businesses to communicate securely and work more efficiently through enterprise-grade protection and AI-driven efficiency.
Enterprise-Grade Security:
Security is at the heart of Coremail’s design. The platform uses end-to-end SSL/TLS encryption for all email transmissions, actively protecting messages and passwords from interception or tampering during transit.
For data stored on the server, Coremail uses encryption and compression algorithms to safeguard sensitive information even in the event of a data breach, while also reducing storage requirements.
To strengthen account protection, Coremail provides Two-Factor Authentication (2FA) and supports various verification methods — such as passwords combined with OTPs or hardware-based authentication. Administrators can also enforce strong password policies and receive alerts for logins from new or unrecognized devices, reinforcing a Zero-Trust security posture.
Additionally, Coremail uses dual anti-virus engines and Safe Browsing technology to detect phishing attempts, malicious attachments, and suspicious links in real time. With this multi-layered defense, Coremail helps organizations maintain compliance with data protection laws such as PDPA in Thailand and other international security standards.
Smart AI Integration:
Coremail integrates artificial intelligence (AI) to simplify daily email tasks and boost productivity. Users can benefit from intelligent tools such as:
- Smart Drafting to help compose emails faster.
- Proofreading and grammar correction.
- Automatic translation.
- Email summarization for quick content review.
What makes Coremail truly stand out is its ability to connect seamlessly with leading Large Language Models (LLMs) like DeepSeek, OpenAI, Azure OpenAI, and popular Chinese AI models — all through a plug-and-play architecture.
This flexibility allows organizations to integrate AI into their email environment effortlessly, enhancing efficiency and adaptability without needing to modify their core infrastructure. It’s one of Coremail’s most distinctive advantages over traditional enterprise email solutions.
High Availability:
For enterprise environments, email uptime and service continuity are mission-critical. Coremail is designed with High Availability (HA) architecture to ensure that operations continue smoothly even in the event of hardware or network failures.
Multiple servers operate in a Multi-Active configuration, supported by an Automatic Failover system that instantly transfers workloads if any node experiences downtime.
The latest version, Coremail XT6, includes 22 modular components within a multi-active cluster architecture, offering exceptional fault tolerance and minimal service disruption. Even during hardware outages or network incidents, communication remains stable — ensuring that business operations never stop.
Scalability and Seamless Migration:
Coremail scales effortlessly to match the growth of any organization. Its container- and cloud-based architecture supports Dynamic Expansion and Elastic Scaling, allowing IT teams to increase capacity within minutes as user demand or data volume grows.
For businesses transitioning from legacy email systems, Coremail provides built-in migration tools for smooth, risk-free deployment. Using methods like Parallel Deployment and Gradual Migration, organizations can move from systems such as Microsoft Exchange or IBM Domino without downtime or data loss — ensuring business continuity throughout the transition.
User Experience and Productivity:
Coremail focuses heavily on user experience, creating an interface that’s intuitive, efficient, and tailored for how modern employees work.
Key features include:
- Automatic Email Categorization for better inbox organization.
- A Feature-Rich Editor that supports advanced formatting, tables, and inline images for professional-looking emails.
- An enhanced Calendar Function that allows file attachments, flexible meeting scheduling, and rich-text descriptions.
Coremail also provides seamless access across multiple devices — desktops, laptops, tablets, and smartphones — ensuring productivity anywhere. Mobile device management policies help administrators define approved devices, set unique app passwords, and enforce security compliance across all endpoints.
By combining a smooth user experience with enterprise-grade security, Coremail empowers employees to collaborate efficiently and confidently within a secure digital environment.
Technical Overview of Coremail
System Architecture and User Scalability
Coremail is built with a robust system architecture that prioritizes both stability and scalability, ensuring smooth and reliable operations for enterprises of all sizes. The latest version, Coremail XT6, is designed to support containerized deployment, allowing it to operate seamlessly in cloud or virtualized environments.
By leveraging container technology, Coremail enables organizations to deploy, scale, and update their email systems with ease.
The platform supports automatic scale-out, dynamically adjusting capacity based on system load.
This makes it easier for businesses to migrate their email infrastructure to the cloud — achieving an “easy cloud transition” without the need for major system restructuring.
Coremail is built on a modular architecture with more than 20 functional components, each managing specific system tasks. This design enables workloads to be shared efficiently across multiple server nodes, allowing Coremail to support a large number of users at once without performance slowdowns.
To boost speed and reliability, Coremail uses Content Delivery Network (CDN) technology to balance webmail and attachment traffic. This helps reduce bandwidth usage by around 20–30% and lowers latency, ensuring fast and smooth access for users in different locations.
With this high level of performance and scalability, Coremail has become the primary email platform for major internet service providers in China, including Netease — operator of @163.com and @126.com, which serve hundreds of millions of users.
Over time, Coremail has also expanded its reach to government organizations, universities, and large enterprises, solidifying its reputation as a reliable and enterprise-ready email solution.
Another core architectural strength of Coremail is its ability to operate in a Multi-Active Data Center environment.
This setup allows multiple data centers to run simultaneously in an active–active configuration, enhancing fault tolerance and improving access speed by automatically directing users to the nearest available data center.
When combined with Coremail’s automatic failover mechanism, the platform delivers continuous and highly reliable service, minimizing the risk of any full-scale system outage.
For organizations that value data protection and business continuity, Coremail also provides a Multi-Active Disaster Recovery framework that keeps data synchronized across all data centers in real time.
This approach significantly reduces data loss and shortens downtime — even in cases of unexpected failures or large-scale disruptions affecting one site.
Security and Data Encryption
Coremail adopts a multi-layered security framework to protect both the system and organizational email data — from transmission to storage — ensuring complete end-to-end protection.
One of the key layers is data encryption. Coremail supports SSL/TLS encryption across all major protocols — including SMTP, IMAP, POP3, and Webmail — to safeguard emails and passwords transmitted over the network from man-in-the-middle attacks.
For data at rest, Coremail encrypts or stores information in compressed binary form using a proprietary algorithm, making it unreadable even in the event of a data breach. This approach not only enhances data security but also helps reduce storage requirements.
Coremail strengthens account protection with multi-factor authentication (MFA), allowing multiple verification methods such as password + OTP or device-based authentication. Administrators can enforce strong password policies — including minimum length, use of special characters, and other criteria — and set up alerts for logins from unfamiliar devices or locations. These features help organizations adopt a Zero Trust security model, ensuring that every user and device is verified before gaining access to the system.
Coremail provides multi-layered protection to defend organizations against email-borne cyber threats. Its security system starts with dual antivirus engines powered by Kaspersky and Qi-Anxin, which scan emails and attachments for malware and viruses — even detecting encrypted files often used to conceal malicious payloads.
To combat spam and phishing attacks, Coremail employs a layered detection system that analyzes message content, checks URLs against a Safe Browsing database, and leverages AI-driven Nerve 2.0 to identify new and evolving attack patterns in real time. This intelligent filtering ensures that users are protected from deceptive links and harmful attachments before they ever reach the inbox.
With these technologies working together, Coremail achieves 99.8% filtering accuracy, according to data from the Coremail Security Gateway. The platform protects over 250,000 users daily, processes more than 30 million suspicious emails, and blocks over 1 million malicious messages every day — all while maintaining optimal system performance.
By combining antivirus, AI analysis, and adaptive threat intelligence, Coremail delivers comprehensive, end-to-end protection that keeps organizational communication secure, reliable, and uninterrupted in today’s complex threat landscape.
Email Data Leakage Prevention (EDLP)
Coremail also offers an advanced Email Data Leakage Prevention (EDLP) solution designed to protect organizations from unintentional or unauthorized data sharing. By using content-aware analysis, EDLP can detect sensitive information — such as confidential documents or internal data — before it leaves the organization via email.
The system allows administrators to set flexible response rules, including post-audit alerts or real-time interception of restricted messages, ensuring strict and accurate data control. In addition, the Security Management Center provides real-time visibility into email activities, enabling administrators to monitor system behavior, identify potential risks, and respond quickly to security incidents.
System Integration, API, and AI Support
Coremail is designed for seamless integration with an organization’s existing IT environment. Businesses that use Microsoft Active Directory (AD) or LDAP for user management can easily connect Coremail to their existing user databases, allowing employees to log in with their current organizational credentials — eliminating the need to create new accounts and simplifying administration.
On the communication side, Coremail fully supports standard email protocols such as SMTP, IMAP, and POP3, ensuring compatibility with a wide range of email clients and devices — including Microsoft Outlook, Apple Mail, and mobile devices via ActiveSync.
Furthermore, Coremail can work alongside existing email platforms within the organization, such as Microsoft Exchange Server or Lotus Notes/Domino, operating as an email relay or gateway without connection issues. For instance, the Coremail Security Gateway can filter and secure email traffic for multiple servers simultaneously — including Exchange, Office 365 (O365), Gmail, and IBM Domino — providing unified protection across different environments.
In addition, Coremail provides a flexible API framework that allows developers to extend or integrate its email functionalities with other enterprise systems. Through RESTful APIs and Web Services, organizations can manage mailboxes, automate user provisioning, or connect Coremail with internal notification platforms and business applications. (Detailed API documentation is available in the official technical guide.)
A key strength of Coremail today lies in its ability to seamlessly integrate external AI technologies. With its dedicated LLM Integration Module, Coremail can connect to leading Large Language Models (LLMs) such as OpenAI, Azure OpenAI, DeepSeek, Ollama, and other top Chinese language models — all through a simple plug-and-play configuration.
This flexibility allows organizations to choose the AI provider that best fits their needs in terms of cost, data security, and language expertise. Coremail’s infrastructure already supports these integrations, enabling advanced AI-driven email features such as semantic content analysis, intelligent categorization, and automated email interaction — helping enterprises communicate smarter, faster, and more adaptively for the future.
Beyond AI capabilities, Coremail is highly customizable to fit the unique needs of every organization.
Businesses can choose between two deployment options — On-Premises, for full control over configuration and security, or Cloud Service (SaaS), where Coremail manages the hosting and maintenance entirely.
For on-premises deployments, organizations can easily customize the user interface, workflows, and add-on plugins to match their internal processes. They can also develop new features or integrate other systems via API if they have in-house technical expertise.
This flexibility ensures that Coremail adapts seamlessly to each organization’s IT environment — whether managed locally or through the cloud.
Comparing Coremail with Other Enterprise Email Platforms
The enterprise email market is highly competitive, with several major players offering a wide range of solutions.
In addition to Coremail, popular platforms include Microsoft Exchange, Zimbra, and Google Workspace (Gmail for Business), as well as other alternatives such as IBM Lotus Notes/Domino, IceWarp, and Zoho Mail.
Each platform has its own strengths and weaknesses. Below is a comparison of Coremail against these leading enterprise email solutions in key aspects.
Microsoft Exchange
- Microsoft Exchange is one of the most trusted and long-standing enterprise email platforms. It is widely used by large organizations within Microsoft’s ecosystem. The platform is known for its flexibility, customization, and seamless integration with Outlook, SharePoint, and Teams. It has long been seen as the gold standard for enterprise email. However, the on-premises version (Exchange Server) requires high upfront costs for software, hardware, and storage. This makes it less practical for small and mid-sized companies. Microsoft also offers a cloud version through Exchange Online or Office 365, but full functionality often requires a Microsoft 365 subscription, which increases per-user costs.
Compared to Exchange, Coremail offers similar core features such as email, calendar, and contact management. It also supports Outlook compatibility but with greater cost efficiency and flexibility. It can run on-premises or in the cloud, minimizing setup and maintenance. Coremail’s licensing model also scales more easily with organization size, while Exchange typically uses a fixed per-user plan. This makes Coremail a more affordable and adaptable solution for businesses of all sizes.
Coremail also stands out with its AI-powered features and multilingual support. While Exchange lacks built-in AI, Coremail XT6 includes tools like Smart Drafting and LLM integration. Although Microsoft has added AI through Outlook Copilot, Coremail’s version is more seamless. Its modern, responsive webmail interface performs as well as Outlook Web App and offers stronger support for Asian languages like Thai and Chinese. Through its partnership with THNIC in Thailand since 2021, Coremail fully supports localized email addresses — something Microsoft only recently introduced.
In summary, Coremail is a strong alternative for organizations seeking a more affordable, AI-ready, and flexible enterprise email solution. It integrates smoothly with existing Active Directory (AD) environments, allowing easy migration from Exchange without disrupting existing workflows.
Zimbra
- Zimbra is a widely used open-source email and collaboration platform, popular among organizations aiming to cut software costs. Its main advantage lies in its free open-source version, offering an intuitive webmail interface and essential features like email, calendar, and contact management.Because it runs smoothly on most Linux-based systems without licensing fees, Zimbra remains a cost-effective choice compared to commercial platforms such as Microsoft Exchange.
When compared with Coremail, both systems support on-premises deployment. However, Coremail stands out as a commercial-grade platform with more advanced features, including High Availability Clustering, multi-site Disaster Recovery, data encryption, and AI-powered tools not found in Zimbra. Backed by over 300 professionals and 25 years of experience, Coremail offers faster updates and enterprise-level support. In contrast, Zimbra’s reliance on its open-source community can lead to slower responses to patches and maintenance.
Google Workspace (Gmail for Business)
- Google Workspace (formerly known as G Suite) is Google’s all-in-one cloud platform for businesses, combining key services like Gmail, Google Drive, Docs, Sheets, Slides, and Google Meet into a single ecosystem. Its biggest strengths lie in its user-friendly interface—familiar to anyone who has used Gmail—and its real-time collaboration features that allow multiple users to work seamlessly on shared documents. Over the years, Gmail for Business has become one of the strongest competitors in the enterprise email space, especially for organizations that prefer a fully cloud-based solution without the need to manage servers or hardware.
However, storing all data on Google’s cloud can raise privacy and compliance concerns, especially for regulated industries or countries with strict data protection laws such as Thailand’s PDPA. Some businesses may also find Gmail’s basic 30GB storage per user limiting compared to on-premises systems, which often allow flexible or unlimited capacity.
When compared with Coremail, the key difference lies in control and flexibility. Coremail gives organizations full ownership of their data through on-premises or hybrid deployment while integrating seamlessly with existing systems. Unlike Google Workspace, which offers a convenient but fully cloud-based model, Coremail provides greater customization, multi-provider AI integration, localized data storage, and advanced security features like encryption and DLP—making it a stronger choice for businesses seeking a secure, AI-ready, and highly adaptable enterprise email solution.
Coremail in Thailand
Thailand is entering a new phase of digital transformation, marked by major investments in digital infrastructure and heightened awareness of cybersecurity. Seeing this growth, Coremail has identified Thailand as a key market in Southeast Asia, where demand for secure, cloud-ready, and AI-driven enterprise email solutions continues to rise. To support this vision, Coremail established a local office at Le Concorde Building, Bangkok, and officially launched Coremail XT6 in September 2025. The company also appointed a local representative to oversee sales and after-sales services—demonstrating its strong commitment to serving Thai customers with reliable, localized support.
A major strength of Coremail in Thailand lies in its full support for the Thai language and “.ไทย” domain names, developed in collaboration with the Thai Network Information Center Foundation (THNIC). Through Email Address Internationalization (EAI), Thai users can now send and receive emails using Thai-language addresses at both the domain and username levels. This partnership highlights Coremail’s leadership in local language support and its dedication to inclusivity in digital communication. Furthermore, the platform’s Thai-language interface and documentation make it easy for both users and administrators to operate.
While Thailand’s enterprise email market remains dominated by Microsoft Exchange/Office 365 and Google Workspace, more organizations—especially in the public sector and financial industry—are seeking alternatives that ensure data sovereignty and compliance with Thailand’s PDPA. Coremail’s ability to run on local data centers with 100% organizational control makes it an ideal fit for these needs. At the same time, large enterprises adopting AI-powered workflows are drawn to Coremail’s built-in AI capabilities and flexible integration with external AI providers.
At the product launch in Bangkok, a Coremail representative stated,
“Thailand is one of the fastest-growing digital economies in the region. Businesses here are looking for innovative technologies to stay competitive. Coremail XT6 delivers a secure, intelligent, and user-friendly email platform that not only protects critical business data but also enhances everyday productivity.”
This statement reflects Coremail’s strategic focus on security and AI-driven innovation for Thai enterprises. Moreover, the company’s partnerships with local technology distributors and service providers reinforce its credibility and ensure reliable after-sales support—key factors that Thai organizations consider when selecting enterprise IT solutions.
Trusted by Leading Organizations
Coremail Service Delivery Models
Coremail offers flexible service delivery models designed to meet the diverse needs and budgets of different organizations.
1. On-Premises Deployment
Organizations can purchase and install Coremail software on their own servers—either within their internal data center or at a co-location facility of their choice. This deployment model provides maximum control and customization, allowing IT teams to fully manage configurations, policies, and data security.
It’s ideal for organizations that prefer to keep all email data stored internally and comply with internal governance or data residency requirements.
2. Cloud Service (SaaS)
Coremail also provides a fully managed cloud-based solution under the name Coremail Enterprise Email Cloud.
Hosted on Coremail’s own cloud infrastructure, the service is billed based on the number of users (monthly or annually), offering convenience similar to Microsoft Office 365 or Google Workspace.
With this model, organizations don’t need to maintain any hardware or perform system management, as Coremail delivers end-to-end services—from infrastructure to operations.
The Coremail Cloud platform comes in multiple plans — Professional, Premium, and Enterprise — each offering different storage capacities, advanced features, and levels of customization.
Organizations can choose the plan that best fits their operational and budgetary needs.
A 15-day free trial is also available, allowing customers to experience the service before committing, with no upfront hardware investment required.
3. Support and Additional Services
No matter which deployment model you choose, Coremail provides reliable technical support and maintenance services to keep your system running smoothly.
Customers with annual maintenance agreements receive regular software updates, security patches, and access to quick support through multiple channels — including phone, email, and an online ticket system.
Coremail also offers an Online Support Center and an extensive Knowledge Base, allowing administrators to find solutions anytime.
In Thailand, a dedicated local office and support team ensure fast response times and personalized assistance that truly understands local business needs.
delivers a comprehensive enterprise email solution that meets the needs of modern organizations — from everyday user features to advanced technical tools for IT teams. It stands out for its security, reliability, AI readiness, and flexibility, allowing full customization to match each organization’s unique requirements.
Coremail is an ideal choice for Thai businesses looking for a modern, secure, and intelligent email system designed for today’s digital era.