Best Small Business Mail Servers
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Compare the Top Small Business Mail Servers as of April 2025
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What are Small Business Mail Servers?
A mail server facilitates the sending and receiving of emails. It acts as an intermediary between email senders and receivers, providing a secure communication channel for emails to be stored and routed. Mail servers provide features such as spam filtering, antivirus scanning, storage limits for individual users, message forwarding rules and other services. They are often used by businesses to securely manage their communications with employees, customers and partners. Compare and read user reviews of the best Small Business Mail Servers currently available using the table below. This list is updated regularly.
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1
MDaemon Email Server
MDaemon Technologies
The MDaemon Email Server was one of the first Microsoft Exchange alternatives offered to businesses around the world. It has been developed with the ongoing input from IT professionals seeking an easy-to-use, reliable, and secure mail server that does not require expensive administration or impose high per-user costs. It simplifies messaging and collaboration with a focus on security and privacy, an intuitive, user-friendly web mail design and by offering administrators Mobile Device Management, Business Instant Messaging, Document Sharing, and other enterprise-class features that can be managed with minimal support. MDaemon Email Server supports IMAP, SMTP, and POP3 protocols, and features include: integrated webmail with IM and document sharing, Outlook support, compromised password alerts, color-coded log files for quick and easy troubleshooting, customizable email policy setting to fit your unique network environment, Mobile Device Management, Account Hijack Detection, and more.Starting Price: $360 per year -
2
Microsoft Exchange
Microsoft
Work smarter with business-class email and calendaring. Exchange helps you collaborate on your critical documents and gives you a focused inbox that prioritizes important messages and adapts to your work style, so you can get more done–faster. Get access to a more personalized inbox with helpful features and a smarter, more organized way to view and interact with email. Search enhancements give you faster and more complete results. With Add-ins, get powerful customization and extensibility, which connect you to modern services and internal line-of-business applications. Organize your time with a calendaring system that goes beyond basic scheduling of appointments and commitments. Automatically capture events from email such as flights and hotel reservations, and get suggestions about where to meet based on your location. Microsoft Exchange Online offers a hosted email service for business. Exchange Online helps protect your information with advanced capabilities. -
3
XgenPlus
Bharat Sync Technologies Pvt. Ltd.
XgenPlus is a next-generation, feature-rich, and highly secure email solution designed to meet the growing communication needs of businesses, enterprises, and individuals. Developed by Bharat Sync Technologies Pvt. Ltd., Xgen Email stands out as the first email service in the world to support Internationalized Domain Names (IDN), enabling users to create email addresses in multiple Indian languages such as Hindi, Gujarati, Tamil, Telugu, Punjabi, and Urdu. With cutting-edge security features, real-time tracking, advanced collaboration tools, and seamless mobile and desktop integration, Xgen Email ensures that users get the most efficient, private, and productive email experience. Whether you're a startup, a large enterprise, or an individual professional, Xgen Email is the best choice for a secure, smart, and efficient email solution.Starting Price: Free -
4
hMailServer
hMailServer
hMailServer is a free, open source, e-mail server for Microsoft Windows. It's used by Internet service providers, companies, governments, schools and enthusiasts in all parts of the world. It supports the common e-mail protocols (IMAP, SMTP and POP3) and can easily be integrated with many existing web mail systems. It has flexible score-based spam protection and can attach to your virus scanner to scan all incoming and outgoing email.Starting Price: Free -
5
Kerio Connect
Aurea
Secure, enterprise-style email, calendar & collaboration without the high cost. Kerio Connect delivers all the features and functionality for collaboration and messaging solution without the complexity and high price tag of other systems. Email is integrated with shared calendars and scheduling, contacts management, tasks, notes, shared and public folders, and instant messaging. Synchronize messages by direct push to your choice of mobile device via Microsoft ActiveSync. Instant Messaging is XMPP-compatible and can be used from various 3rd party chat/IM applications on desktop and mobile phones. You can install Kerio Connect in 10 minutes and users can be up and running in just 10 minutes more. Kerio Connect can be deployed on-premises or in partner-hosted cloud environments. Deploy for users on Mac, Windows, or Linux; plus full support for Outlook (Windows and Mac) and many other IMAP or POP compliant email clients.Starting Price: $36.50 -
6
Kingmailer
KingSMTP.com
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.Starting Price: $0 per month -
7
SmarterMail
SmarterTools
SmarterMail is the ideal Microsoft Exchange alternative. It’s the only business email server on the market that offers native support for Exchange protocols: MAPI, EWS, and EAS, without requiring any additional software or plug-ins for Microsoft Outlook or other desktop or mobile clients. It delivers all the features of Exchange at a fraction of the cost. SmarterMail also includes audio/video group chat and Online Meetings for team collaboration at no extra charge. Its newest feature, the SmarterMail Marketplace, enables seamless integration with platforms like OnlyOffice, Collabora, and AI tools such as OpenAI’s ChatGPT. Available for both Windows and Linux, SmarterMail has lower hardware requirements, superior stability, and reduced maintenance costs. It’s the perfect solution for businesses of any size or industry seeking Exchange-level functionality, without the high costs.Starting Price: $500.00/one-time -
8
KumoMTA
Kumo Corp
KumoMTA is an Open-Source, enterprise-grade email message transfer agent (MTA) software for sending high-volume, business-critical emails. KumoMTA is typically chosen by high-volume email users looking to replace PowerMTA, Momentum, or traditional Open Source MTAs. KumoMTA offers high-performance message relay to the tune of millions of messages per hour per server, combined with extreme flexibility and configurability through its use of a Lua scripting engine for configuration and message management. For more information on KumoMTA see our Sourceforge project page.Starting Price: $0 -
9
Axigen
Axigen Messaging
Offer your customers secure, business-level email hosting with various value added services. An excellent solution for SPs, suitable for thousands to millions of users. Acquire new customers by offering a premium email server solution with a high degree of flexibility, allowing you to automate it within your existing infrastructure. Manage your email, organize and share calendars, sync your mobile devices, all based on a secure and powerful mail server. The perfect answer for businesses of all sizes. Axigen is quite knowledgeable, out of the many hats it wears, take a peek inside and choose what fits you. Manage your email and get stuff done easily with calendars, tasks or notes. Enjoy desktop usability in your browser via keyboard navigation and shortcuts, drag-and-drop, "live" email list view, frequent folders, email filters, out-of-office messages, individual blacklist / whitelist.Starting Price: $266 per year -
10
MailSite Fusion
Rockliffe Systems
MailSite Fusion is a Windows email, calendar and contact server with over-the-air push to all types of smartphones, Full native Outlook sync, a sophisticated AJAX web client and a calendar and contact sharing server, which can synchronize and publish to many other clients. MailSite has been voted in the top 3 mail server products by readers of Windows IT Pro Magazine 3 years running. Your email services are critical to your organization. So you need to be sure that you select a quality product, from a company with a proven track record in communication software. So, why this mail server? Because Rockliffe understands your concerns, we have been specializing in developing and refining our email server and email security software for business and service providers since 1995. Built from the ground up to be fast, stable and secure, MailSite Fusion is ready to meet the needs and requirements that matter to you most.Starting Price: $90 per year -
11
Kolab Now
Apheleia IT AG
Secure and private email, calendars and more. 100% Free & Open Source Software (FOSS). Open standards and formats used for all storage and communication. No vendor lock-in. All data stored under Swiss jurisdiction. User data never transmitted to any third party without explicit consent. GDPR, HIPPA and PCI compliant. Built secure from the ground up. Supports perfect forward secrecy (PFS). End-to-end encryption available. No back doors. Our documentation contains answers to most frequently asked questions and much more. Are you looking for an instant answer to your question or a quick solution for your problem, our Knowledgebase is where you will likely find it. If you can’t find the answer in our documentation, you can always contact support.Starting Price: $9.90 per month -
12
NethServer
NethServer
Analyzes all web traffic and blocks selected websites via HTTP and even HTTPS using Squid proxy. Integrated with ClamAV antivirus and site blacklists. Multi-domain web server with ready LAMP stack. Virtual hosting allows to host multiple domain names on a single server. Based on NextCloud provides universal access to your files via the web, your computer or your mobile devices, wherever you are. Provide a private Slack-alternative with Mattermost. Open source messaging platform that enables secure team collaboration. Modern and powerful web interface based on Cockpit that simplifies common administration tasks, very easy and fast installation. Based on CentOS/RHEL, a widespread and popular server distribution, trusted by routine security updates, and rock solid stability.Starting Price: €48 per year -
13
Zentyal
Zentyal
Join Windows® clients to the domain and manage them transparently. No disruption to your users, no user or device CALs. Comes with industry-standard SMTP and POP3/IMAP mail server built upon the most established technologies and protocols. Guarantees reliable and secure Internet access and helps to manage all the basic network infrastructure services. Receive software updates until the EOL-date of each version and get support when needed. Zentyal offers an easy to use Windows Server® alternative. It comes with native compatibility with Microsoft Active Directory® allowing you to join Windows® clients to the domain and manage them easily, causing no disruption to your users. Zentyal includes the industry-standard SMTP and POP3/IMAP mail servers built upon the most established technologies and protocols. Gives you the opportunity to deploy Zentyal as a mail server, domain & directory server with mail or all-in one server.Starting Price: €195 per server -
14
iRedMail
iRedMail
The right way to build your mail server with open source softwares. Works on CentOS Stream, Rocky, Alma, Debian, Ubuntu, FreeBSD, OpenBSD. With iRedMail, you can deploy an OPEN SOURCE, FULLY FLEDGED, FULL-FEATURED mail server in several minutes, for free. We did the heavy lifting of putting all the open source components together and applying best practices. Our product does all the major tasks for you. Furthermore we offer professional support to back you up in case you have some problems. You have all personal data on your own hard disk, you can control the email security, inspect transaction log. No other organization can see the content of all messages. All components used in iRedMail are open source softwares, and you get the bug fixes and updates from the Linux/BSD venders you trust. iRedMail is the right way to build your mail server with open source softwares.Starting Price: Free -
15
Mail-in-a-Box
Mail-in-a-Box
Mail-in-a-Box lets you become your own mail service provider in a few easy steps. It’s sort of like making your own gmail, but one you control from top to bottom. Technically, Mail-in-a-Box turns a fresh cloud computer into a working mail server. But you don’t need to be a technology expert to set it up. Each Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software. It also includes contacts and calendar synchronization. The box also includes other standard mail functionality like spam protection (spam filtering and greylisting), mail filter rules, email client autoconfiguration, and automated backups to Amazon S3 and other services. The box also includes automatic DNS configuration when you let it become your nameserver so that it can set important DNS records for mail deliverability and security including SPF, DKIM, DMARC, and MTA-STS. When enabled, DNSSEC (with DANE TLSA) provides a higher level of protection.Starting Price: Free -
16
Modoboa
Modoboa
Regain your independence and protect your privacy by installing your own email server. It takes less than 10 minutes! Create your mail server for free in less than 10 minutes with Modoboa When it comes to create a mailbox, you generally have several solutions: - Use the services offered by Internet providers (Orange, Vodafone...) of infrastructure providers (OVH, Gandi...) with a monthly or annual subscription. However, customization and configuration possibilities, domains and mailboxes number are limited. - Use the services of free email providers (Gmail, Live, Yahoo...) which are limited and your data is used for commercial purposes. - Install your own email server, which requires important technical knowledge to setup and configure the system. Modoboa is an alternative to those 3 options. It frees you from dependence on email providers and makes accessible to all the creation his own secure email server. The whole thing, in less than 10 minutes and freely.Starting Price: Free -
17
Mailu
Mailu
Mailu is a simple yet full-featured mail server as a set of Docker images. It is free software (both as in free beer & as in free speech), open to suggestions and external contributions. The project aims at providing people with an easily setup, easily maintained and full-featured mail server while not shipping proprietary software nor unrelated features often found in popular groupware. Main features include: Standard email server, IMAP and IMAP+, SMTP and Submission with autoconfiguration profiles for clients Advanced email features, aliases, domain aliases, custom routing Web access, multiple Webmails and administration interface User features, aliases, auto-reply, auto-forward, fetched accounts Admin features, global admins, announcements, per-domain delegation, quotas Security, enforced TLS, DANE, MTA-STS, Letsencrypt!, outgoing DKIM, anti-virus scanner, Snuffleupagus, block malicious attachments Antispam, auto-learn, greylisting, DMARC& SPF, anti-spoofingStarting Price: Free -
18
MailEnable
MailEnable
MailEnable provides an end to end solution for providing secure email and collaboration services. A recent independent survey reports MailEnable as the most popular Windows Mail Server Platform in the world. Whether you are a hosting company providing email services to thousands of end users or a small business with a single domain, MailEnable provides a solution that will impress your mail users. MailEnable provides Windows Mail Server software with features comparable to Microsoft Exchange. It provides powerful messaging services like Exchange ActiveSync, IMAP, SMTP, POP3 and collaboration tools such as calendaring (CalDAV), contacts (CardDAV), tasks and notes.Starting Price: $349 -
19
Apache James
The Apache Software Foundation
James stands for Java Apache Mail Enterprise Server. It has a modular architecture based on a rich set of modern and efficient components which provides at the end complete, stable, secure, and extendable Mail Servers running on the JVM. Create your own personal solution of email treatment by assembling the components you need thanks to the Inversion of Control mail platform offered and go further customizing filtering and routing rules using James Mailet Container. The Apache James project wires together the different libraries composing James to provide running services, ready to download on the Apache mirrors.Starting Price: Free -
20
Horde
Horde
Horde is the most flexible groupware on the planet, and that makes it the perfect platform on which to build your business productivity software. Horde connects to (and officially supports) more backends (all the leading SQL, LDAP, IMAP, Sieve, SMTP, cache platforms available today) than any other open source groupware system. This means you can continue to use your existing userbase and your users do not have to remember any additional passwords. Horde's feature set rivals the largest enterprise email systems. We have an incredible feature set that compares favorably against any competition in our primary apps (mail, calendar, address book), and even more in our secondary apps (time tracking, wiki, ticketing, and more).Starting Price: Free -
21
Eudora Internet Mail Server
Eudora Internet Mail Server
Completely rewritten relay restrictions with an easier to use interface that gives finer control over relay security. New domain name resolver (DNR), EIMS now has it's own DNR, which works around bugs in the Open Transport DNR and performance problems with the OS X DNR. The new DNR does not currently support non-recursive DNSs. SMTP Submit port, this is a second SMTP port running on TCP port 587 by default. It currently works exactly the same as the standard SMTP port. This is handy for clients that are stuck behind an ISP that blocks port 25 access. Sending Setup option for maximum recipients per message. Expand SMTP Addresses option, you can now turn this off, with EIMS 3.1 and earlier it was always on. The SMTP server (both port 25 and 587) now reports Telnet connections and connections that look like port scans (connections where no data is sent and it doesn't time out).Starting Price: Free -
22
Haraka
Haraka
Haraka can serve thousands of concurrent connections and deliver thousands of messages per second. Haraka and plugins are written in asynchronous JS and are very fast. Haraka has very good spam protection (see plugins) and works well as a filtering MTA. It also works well as an MSA running on port 587 with auth and dkim_sign plugins enabled. Haraka makes no attempt to be a mail store (like an exchange or postfix/exim/qmail), an LDA, or an IMAP server (like Dovecot or courier). Haraka is typically used with such systems. Haraka has a scalable outbound mail delivery engine built in. Mail marked as relaying (such as via an auth plugin) is automatically queued for outbound delivery. Haraka's plugin architecture provides an easily extensible MTA that complements traditional MTAs that excel at managing mail stores but do not have sufficient filtering.Starting Price: Free -
23
OpenSMTPD
OpenSMTPD
OpenSMTPD is a free implementation of the server-side SMTP protocol as defined by RFC 5321, with some additional standard extensions. It allows ordinary machines to exchange emails with other systems speaking the SMTP protocol. Started out of dissatisfaction with other implementations, OpenSMTPD is a fairly complete SMTP implementation. OpenSMTPD is primarily developed by Gilles Chehade and Eric Faurot, with contributions from various OpenBSD hackers and members from other communities.Starting Price: Free -
24
SOGo
SOGo
SOGo is a fully supported and trusted groupware server with a focus on scalability and open standards. SOGo is released under the GNU GPL/LGPL v2 and above. SOGo provides a rich AJAX-based Web interface and supports multiple native clients through the use of standard protocols such as CalDAV, CardDAV and GroupDAV, as well as Microsoft ActiveSync. SOGo is the missing component of your infrastructure; it sits in the middle of your servers to offer your users a uniform and complete interface to access their information. It has been deployed in production environments where thousands of users are involved. -
25
Scalix
Scalix
Offer a high value Outlook experience with push email, PIM, group calendaring, free/busy services, public folders, delegation, and more. Increase margins with lower server counts and compelling subscription pricing. Reduce your licensing costs and leverage your teams' existing skills with a Linux-based platform. Scalix starter packs are robust, single-server messaging solutions designed to provide smaller businesses and organizations with a full featured email and collaboration solution. Scalix small business edition is our single-server solution designed for small businesses. It includes a rich package of business functionality including a means to instantly recover deleted items on a user-specific basis, wireless device support and more. -
26
Dovecot
Dovecot
Dovecot is an excellent choice for both small and large installations. Dovecot is among the best performing IMAP servers while still supporting the standard mbox and Maildir formats. The mailboxes are transparently indexed, which gives Dovecot its good performance while still providing full compatibility with existing mailbox handling tools. Dovecot is standards compliant. Dovecot passes all IMAP server standard compliancy tests while most other servers fail many of them. Dovecot’s indexes are self-optimizing. They contain exactly what the user’s client commonly needs, no more and no less. Dovecot is self-healing. It tries to fix most of the problems it notices by itself, such as broken index files. The problems are however logged so the administrator can later try to figure out what caused them. Dovecot tries to be admin-friendly. Common error messages are made as easily understandable as possible.Starting Price: Free -
27
mailcow
mailcow
mailcow: dockerized is an open source groupware/email suite based on Docker. mailcow relies on many well known and long used components, which in combination result in an all around carefree email server. Each container represents a single application, connected in a bridged network.Starting Price: Free -
28
Poste.io
analogic
You can have a fully functional mail server installed in a few minutes, mostly waiting for scripts to do the work. The whole package is designed with reasonable defaults to get you up and running quickly, without having to know the internals and without making decisions that could break the email system. User data and configuration is strictly separated from binaries. User database is stored in SQLite database - in file. This makes Poste.io fully compatible with external storage. Migration, backups or updates are therefore very easy and mostly consist of files manipulation. Poste.io has been built from the ground up with security in mind. Internet history is littered with painful security incidents, so we traded old email client compatibility and insecure authentication methods for features that meet today's for features that meet modern security requirements.Starting Price: Free -
29
Citadel
Citadel
Email, collaboration, groupware, and content management - up and running in minutes, on your own hardware, or in the cloud. Citadel is easy, versatile, and powerful, thanks to its exclusive room-based architecture. No other platform seamlessly combines so many different features using this familiar and consistent metaphor. Citadel is 100% open source software using the GNU General Public License. It's not a crippled, cut-down version of some expensive "enterprise" edition. The software you download here is the very best available, and it's all free software.Starting Price: Free -
30
Mailtraq
Mailtraq
Mailtraq Professional mail server software is the complete email server for business. It does everything you need at a great price and without hassles. Mailtraq is the ideal Microsoft Exchange Alternative: easy to deploy and simple to manage. Low license cost, no server-CALs, and stability in operation make Mailtraq email server software the choice for all SMB and SOHO businesses. Email is at the heart of your company or organization, and where those messages are stored is of vital importance to the long-term health of your firm. There is a degree of hassle and expense involved in running your own email server but it gives you complete physical control over who has access to your email. If you use your ISP's service then their system administrators can see and read your messages. Similarly, if you use a SAAS supplier for a hosted email service, and if you use a Cloud provider you not only don't know who is reading your email, but don't even know where in the world it is kept.