It’s fair to say that sending and receiving email was our first connection to others via the Internet. Email is sent and received by mail servers based on a combination of many interconnected servers. In this context, the best Linux mail servers will be introduced to help you know and use them. This content will be useful if you have your own business as finding an ideal mail server enables you to manage your daily emails and enjoy its other benefits. Because Linux is lightweight and customizable, it is a good choice for hosting mail servers. Regardless of where you are located and which distro is your favorite, operaVPS offers you a perfect Linux VPS to host your own mail server software.
What is a mail server and how does it work?
The computerized system that can send and receive email is called a mail server. These systems usually consist of many connected servers that work together to send messages to the right people. Although it takes only one second to send an email, several transfers from one mail server to another are required. Emails are moved from one Internet location to another by using a Linux mail server program. They are also called Mail Transfer Agents (MTAs), and they are responsible for receiving incoming emails from other servers and passing them to the user’s client software and back again. Although almost all mail servers are capable of handling both incoming and outgoing emails, the two tasks are separate and adhere to different protocols. Post Office Protocol 3 (POP3) or Internet Message Access Protocol (IMAP) is typically used by an incoming mail server, and Simple Mail Transfer Protocol (SMTP) is used to deliver emails already received by the user’s client software.
A small mail server may be all you need if your business is small and has only a few users. If you have a large number of users, a more powerful server will be needed. Stay tuned as we review the top 15 Linux mail servers to find out which one meets your needs and covers your specific situation. Before that, you should know how to choose an ideal mail server for Linux.
Options must be checked when selecting a mail server
There are several factors to consider when choosing a mail server. Let’s review the most important features you need to consider when choosing a mail server.
1. Security
When it comes to managing mail servers, security features are very important. To prevent unwanted access, many providers offer not just one but multiple authentication features. A responsive alarm system for your mail server is something you should consider. This way, if there is a security issue, you will be notified immediately. Additional security features include SMTP filtering, real-time black-listing, and IP-based authentication.
2. Scalability
When your firm is aiming for growth you must consider the scalability factor to handle thousands of users. To understand mail server scaling you must be aware of your company’s product support system and monitor the performance of the IO subsystem. These can help you determine how much additional hardware you need to fill out. To get a more accurate picture, you need to additionally consider service costs and logging volumes.
3. Integration
If you invest a lot of money in mail servers, you probably want to integrate them with software from other companies to make their jobs easier. You must examine the design and inner workings of a mail server to determine whether it can coexist with other programs. It is possible to tell whether a mail server has the necessary architecture to successfully integrate third-party software by looking at its speed and efficiency.
4. Functionality
Over the past ten years, the ability of mail servers to send, receive, and provide access to a variety of messages has grown significantly. The operation of these servers is always linked to basic components like POP, SMTP, and webmail To improve the functionality of your mail server, you can also add specific features.
5. Management of Antivirus and Antispam
Malware can leak private communications to other servers, so it’s crucial to prevent it from getting into your mail server. Attachment control, automatic virus definition file download, and several scan options are some of the aspects taken into consideration for antivirus management. When managing anti-spam you should look for download filters, sender checks and mail reports. You can use these tools to help you in any emergency or situation.
6. Migration Support Services
If you ever need to transfer data from one mail system to another, it will cost you a lot of money. For this reason, you should choose a server with support for MDIR or MBOX format migration. If servers provide access interfaces, configuration data migration is also possible.
Best Linux Mail Servers
In this part, you will get to know the best mail servers for Linux and learn about their pros and cons to be able to decide which one suits your needs. Let’s begin.
1. Exim
Exim is considered by many experts to be one of the best mail servers available. It is free software present on most Unix-like operating systems. On Debian Linux systems, its fourth version acts as the MTA by default. Exim is a mail server with many capabilities, each of which completes a specific task. The most important advantage of using Exim as your mail server is that it offers flexibility in terms of customization and configuration. It has the best transfer agent, which can be easily customized to any corporate setting. The GNU GPL license allows administrators to modify the original program because this mail server runs on the Linux operating system. Overall, if you need a Linux mail server, Exim is a solid choice, especially if you need something that’s extremely flexible.
Exim Advantages
- Even for beginners, it is quite easy to set up and operate it.
- GNU GPL License0.
- Exim is also very efficient and adept at handling high mail volumes.
- System-wide message filtering.
- Exim is a highly adaptable mail server that can be set up to meet a variety of requirements.
- Encrypted SMTP connections using SSL/TLS.
- External authenticator.
Exim Disadvantages
- If you experience difficulties, less community support may be accessible.
- Exim can be difficult to configure if you need the bare minimum features.
- It is not as popular as some other mail servers which may be a bug.
2. Zimbra
Zimbra is one of the top 15 Linux mail servers. It surpasses a Linux distribution in terms of power and functionality. Offering additional features such as group calendars and practical UI menus fosters a welcoming user experience. These mail server recovery options are impressive because they go beyond security. An open source, a powerful Linux mail server with many powers is called the GIMBRA email server. It is scleble, protected and easily usable. It supports broad hardware and operating systems.f So it’s a fantastic option for companies of all sizes. Additionally, Zimbra has a great user base that is constantly ready to help. Zimbra offers users a one-click disaster recovery tool that increases its reliability in the event of an emergency or server failure. This is a great choice if you are looking for an email server that can accommodate your needs. It is well known for its reliability and security and is used by millions of people worldwide.
Overall, organizations of all sizes should consider using Zimbra as their mail server. Although it has many features and flexibility, it can be resource-intensive and challenging to master for beginners.
Zimbra Advantages
- Free and open source.
- Zimbra has high scalability, so it can change as your company’s needs change.
- Mobile web client application.
- It is relatively easy to set up and operate even for those with little experience.
- Backup feature.
- Zimbra is a very feature-rich mail server that offers a variety of options and tools to control your email system.
- Group calendar and document sharing.
Zimbra Disadvantages
- For new users, the interface can be a little intimidating.
- Zimbra may not be suitable for use on servers with low processing power as it can be rather resource-intensive.
3. Sendmail
Sendmail is one of the top 15 Linux mail servers that can also be used on Windows NT. The first version of SendMail, a general-purpose email routing system, was introduced in 1983. SendMail is a well-known MTA that provides a flexible selection of email delivery methods and is free. Sendmail can batch-read multiple addresses on a single host machine because it doesn’t require a lot of network capacity. It uses configuration files to execute instructions for customization. The fact that Sendmail uses protocol-compliant delivery techniques has contributed to its popularity. A server attempts to deliver emails to their intended recipients as soon as they are received. It queues messages to be sent later if the recipient is absent. In fact, it does not provide any mailbox service. Therefore, additional software is required, such as POP3 and Internet Message Access Protocol.
Sendmail facility
- Requires little network bandwidth.
- It is easy to configure and set up.
- Customized email forwarding capabilities.
- It integrates effectively with other programs such as spam filters
- A very reliable and stable mail server is Sendmail. Many large companies use it and it has been around for a while.
Sendmail Disadvantages
- Sendmail configuration can be difficult if you want to do more than the bare minimum.
- It doesn’t have bells and whistles like some recent mail servers
4. Qmail
It’s one of the best and most popular Linux mail servers. This is a great alternative to Sendmail. The SMTP protocol ensures this claim by providing various credentials through the queue manager or SMTP sender, and security is the biggest benefit for customers. It is considered one of the top 15 Linux mail servers due to its popularity and ease of use during setup. As a simple email manager, Qmial is easy to use and stable enough to provide a secure environment.
Qmail Advantages
- Support for QMT.
- Allows you to replace any single part of the system with alternative modules.
- VERPs, EZMLM mailing list management, and automatic host configuration are provided.
- Supports various operating systems including Linux, Solaris, Mac OS X, and BSD.
- Manage customized mailing lists and assist with automatic detection and avoidance of mailing loops.
- Wildcard mailboxes with user controls.
Qmail difficulties
- It does not allow internet connection using IPv6.
- Many options, such as for outgoing SMTP messages, etc., have hard-coded upper limits.
- Accounts cannot be configured using a regular method. The overall design is written to maintain a static interface.
- Users may be confused by the queue structure used to hold emails.
- Although Qmail is open source, it is not free to use. Its distribution is noticeably slower, and sending binaries to customers is not an option.
5. Citadel
Citadel is undoubtedly the greatest mail server for Linux. This powerful and highly versatile email architecture stands the test for its exceptional performance and adaptive features despite being released 33 years ago. This mail server is a general-purpose groupware and collaboration suite designed to work with BSD Unix distributions and open-source operating systems such as Linux. It stores all its data in the Berkeley database. It is free and open source software that operates under the GNU General Public License. (GPLv2 and GPLv3). Maximum people are familiar with this Linux mail server for its straightforward control interface and fast startup.
Citadel Advantages
- OpenSSL encryption.
- Easy to install and use.
- Schedule
- Built-in implementation of Internet Protocol.
- Keep files.
- Multiple domains support.
Citadel Disadvantages
- Clunky interface.
- Complex configuration for new users.
6. hMailServer
Another free, open-source Linux mail server that’s well-liked in many industries is hMailServer. SPF and SURBL are two built-in anti-spam technologies. hMailServer supports popular protocols like SMTP, POP3, and IMAP. It is associated with a high-security feature that allows authentication and has a simple installation and setting process. It can connect to your virus scanner to scan all incoming and outgoing emails and includes customizable score-based spam protection.
hMailServer facility
- Free and open source.
- It’s quite simple to set up and configure. You will have no problem setting up hMailServer, even if you have never used a mail server before.
- Supports multi-domain.
- Using plugins, you can add more functionality.
- hMailServer is highly reliable and stable.
- SSL encryption.
- Website Administration.
- If you need help configuring something or debugging a problem, you can probably find the solution in the manual.
Disadvantages of hMailServer
- Some sophisticated capabilities seen in other mail servers are missing from -hMailServer. It doesn’t offer antivirus protection or spam filtering, for example.
- Many people don’t use -hMailServer as other mail servers are available. Consequently, less resources are available.
- No formal customer support is offered because hMailServer is open source. If you encounter any problems, you need to rely on the community for support.
7. Modoboa
Modoboa open-source SQL-based Linux mail servers. It provides many essential capabilities from a single user interface, eliminating the need to install each feature separately.
Let’s Encrypt, a non-profit Certificate Authority provides a private and secure mailing option using the TLS protocol. Additionally, it frees you from dependence on email service providers.
Using DMARC, Modoboa is often used with SPF and DKIM protocols. Through a reporting feature, these protocols, which are free email authentication methods for email delivery and security, help senders and recipients monitor and enhance domain defenses against phishing emails. The nice thing about it is that it enables you to set up a fully-functional mail server using the most important features that you can benefit from.
If you are looking for a secure and user-friendly mail server, Modoboa is an excellent option. Anyone looking to set up a new mail server will find it a suitable option due to its straightforward interface and comprehensive security features.
Modoboa facilities
- Easy to use.
- The web interface is simple and easy to use, which makes managing your mail server a pleasure
- With the help of various plugins, Modoboa’s capabilities can be extended as needed.
- Calendar and address book management.
- Uses SSL/TLS connections and encrypted passwords to secure your data.
- Traffic monitoring.
- Offers many additional security measures that can be set, including spam filtering and two-factor authentication.
Modoboa difficulty
Lack of documentation. If you’re having trouble, there isn’t a lot of documentation available to help you.
Compared to other mail servers, it currently has no third-party integrations or plugins available.
8. Postfix
Postfix is now offered under the Eclipse Public License after first being made available in 1998 under the IBM Public License 1.0. VMailer and IBM Secure Mailer are also other names for Postfix. It is compatible with every UNIX-like operating system including BSD, AIX, HP-UX, Linux, macOS and Solaris with C compilers and POSIX development environment. You can route and distribute emails using this powerful open-source mail server. It acts as the standard message transmission agent for NetBSD, macOS, RedHat/CentOS and Ubuntu.
To set up a mail server on a Linux system, Postfix is often used. It includes various features and is easy to configure. A complete mail server solution can be built using Postfix in conjunction with other applications.
Advantages of Postfix
- Safe and fast.
- Easy to install and set up.
- Consumes less memory.
- Virtual domain support.
- It has numerous security and anti-spam features.
- Support for MYSQL, SQLite, PostgreSQL, LDAP, Memcached, CDB, and Berkeley databases.
- Pre-pack content filtering.
- It also has the ability to serve as a relay.
Postfix Disadvantages
- Newbies may find the configuration file confusing.
- There is no web interface.
9. Mail-in-a-Box
One of the top 15 Linux mail servers is Mail-in-a-Box which is an easy-to-use Linux mail server that uses sophisticated security measures. Apart from automatic DNS configuration, spam filtering, greylisting, backup to Amazon S3, static website hosting and simple SSL certificate installation, it also offers you other essential services. With this tool, numerous users can adopt an IMAP/SMTP server for hosted mail, DNS, webmail, and desktop and mobile mail programs.
Mail-in-a-Box Advantages
- Calendar and contact synchronization.
- Free TLS (SSL) certificates from Let’s Encrypt.
- Practicing the latest security methods such as opportunistic TLS, strong ciphers and HST, as well as contemporary mail protocols (SPF, DKIM, and DMARC).
- Set up and configure email with a web-based control panel.
Mail-in-a-Box Disadvantages
- Complex setup process.
- Presence of bugs.
- Software compatibility issues.
- Has an archaic user interface.
10. Cyrus IMAP Server
You can access your personal emails using the IMAP protocol with a powerful Linux mail server known as Cyrus IMAP Server.
It also includes services for contacts and calendars Having numerous services connected to one mail server improves your company’s performance. Users can use IMAP, IMAPS, POP3, and POP3S to access mail servers. A personal mailbox database that effectively optimizes servers for scalability and administration may be useful for you.
Cyrus mail server system software has powerful mail screening features. To remove meaningless communications from users’ accounts, the software employs additional filtering language. Email solutions are produced by the CalDAV & CardDAV protocols. It is important to note that this program is still under development and will receive regular upgrades to correct bugs and issues.
Cyrus IMAP server benefits
- JMAP support.
- Integrates with other applications and systems.
- Highly configurable.
- Substantial documentation and support.
- Supports antivirus and anti-spam toolkits.
Disadvantages of Cyrus IMAP server
- A bit more complicated to install and configure than some other mail servers.
- Since it is not as popular as some other mail servers, there may not be as much community support.
Conclusion
The Best Linux mail servers that you should know and should be used in this tutorial were discussed in this tutorial. The best mail servers were explained and to help you identify which of your choices, the benefits and their consists were also mentioned in detail. Depending on the unique requirements of your company, you can select one of the top mail servers for Linux. Keep in mind that the sequence of mail servers in this article has nothing to do with their superiority, it is just the author’s system.
