Open Source Linux Email Servers
Sort By:
Email Servers for Linux
View 29 business solutionsBrowse free open source Email Servers and projects for Linux below. Use the toggles on the left to filter open source Email Servers by OS, license, language, programming language, and project status.
-
$300 in Free Credit Towards Top Cloud ServicesStart your project in minutes. After credits run out, 20+ products include free monthly usage. Only pay when you're ready to scale.
-
Earn up to 16% annual interest with Nexo.Generate interest, borrow against your crypto, and trade a range of cryptocurrencies — all in one platform. Geographic restrictions, eligibility, and terms apply.
-
1
PHPMailer
The classic email sending library for PHP
PHPMailer – A full-featured email creation and transfer class for PHP. Support for UTF-8 content and 8bit, base64, binary, and quoted-printable encodings. SMTP authentication with LOGIN, PLAIN, CRAM-MD5, and XOAUTH2 mechanisms over SMTPS and SMTP+STARTTLS transports. Validates email addresses automatically. Many PHP developers need to send email from their code. The only PHP function that supports this directly is mail(). However, it does not provide any assistance for making use of popular features such as encryption, authentication, HTML messages, and attachments. Formatting email correctly is surprisingly difficult. There are myriad overlapping (and conflicting) standards, requiring tight adherence to horribly complicated formatting and encoding rules – the vast majority of code that you'll find online that uses the mail() function directly is just plain wrong, if not unsafe! -
2
The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, Webmail, calendaring, and mailing list services.
-
3
MailHog
Web and API based SMTP testing
Inspired by MailCatcher, easier to install. Built with Go, MailHog runs without installation on multiple platforms. Run it from Docker Hub or using the provided Dockerfile. The SMTP server starts on port 1025, the HTTP server starts on port 8025, in-memory message storage. ESMTP server implementing RFC5321. Support for SMTP AUTH (RFC4954) and PIPELINING (RFC2920). Web interface to view messages (plain text, HTML or source). Supports RFC2047 encoded headers. Real-time updates using EventSource. Release messages to real SMTP servers. Chaos Monkey for failure testing. HTTP API to list, retrieve and delete messages. See APIv1 and APIv2 documentation for more information. HTTP basic authentication for MailHog UI and API. Multipart MIME support. Download individual MIME parts. In-memory message storage. MongoDB and file based storage for message persistence. Lightweight and portable. No installation required. -
4
smtp4dev
The fake smtp email server for development and testing
smtp4dev - the fake SMTP email server for development and testing. A dummy SMTP server for Windows, Linux, Mac OS-X (and maybe elsewhere where .NET Core is available). Lets you test your application without spamming your real customers. -
Build Securely on AWS with Proven FrameworksMoving to the cloud brings new challenges. How can you manage a larger attack surface while ensuring great network performance? Turn to Fortinet’s Tested Reference Architectures, blueprints for designing and securing cloud environments built by cybersecurity experts. Learn more and explore use cases in this white paper.
-
5
mailcow
mailcow: dockerized
With the Nightly Branch, it is now possible to use an external Identity Provider as an additional authentication source. mailcow utilizes the OIDC (OpenID Connect) protocol to authenticate only mailbox users. You can also get a SAL which is a one-time payment with no liabilities or returning fees. mailcow makes use of various open-source software. Please assure you agree with their license before using mailcow. Any part of mailcow itself is released under GNU General Public License, Version 3. -
6
ISPConfig - ISP management and Hosting Control Panel. ISPConfig manages one or more webservers, mailservers, BIND DNS server, FTP servers, MySQL databases and virtual Servers with an easy to use webinterface for administrators, resellers and clients.
-
7
PostfixAdmin is a Web Based Management tool created for Postfix. It is a PHP based application that handles Postfix Style Virtual Domains and Users that are stored in MySQL, PostgreSQL or SQLite
-
8
Docker Mailserver
Production-ready fullstack but simple mail server
docker-mailserver provides a production-ready, all-in-one email server in a single container, focused on simplicity and maintainability. It bundles the core mail stack—Postfix for SMTP and Dovecot for IMAP/POP3—then layers in optional anti-spam and anti-virus services, DKIM/DMARC signing and verification, and rate-/abuse-protection tooling. The project emphasizes secure defaults while exposing configuration via environment variables and mounted files, allowing you to define users, aliases, domains, and sieve filters without rebuilding images. It integrates smoothly with Let’s Encrypt for TLS, supports LDAP and other auth backends, and ships with scripts to validate DNS records and common misconfigurations. Persistent volumes keep mailboxes and state, making upgrades straightforward and rollbacks less risky. Administrators appreciate the clear docs, test suite, and opinionated conventions that help avoid fragile bespoke setups. -
9
Mox
modern full-featured open source secure mail server
Mox is a modern email server written in Go that aims to be simple, secure, and standards-compliant. It includes SMTP, IMAP, DMARC, SPF, DKIM, and other protocols required to host email services. Designed for self-hosters and developers who want better control over their email stack, Mox focuses on code clarity, privacy, and correctness, offering a complete mail server solution that is easy to set up and maintain. -
Our Free Plans just got better! | Auth0You asked, we delivered! Auth0 is excited to expand our Free and Paid plans to include more options so you can focus on building, deploying, and scaling applications without having to worry about your security. Auth0 now, thank yourself later.
-
10
Postal
A fully featured open source mail delivery platform for incoming
Postal is a complete, open-source mail delivery platform for managing massively scalable outgoing email infrastructure—designed as a self-hosted alternative to SendGrid, Mailgun, or Postmark. It provides a web UI for managing email streams, logs, and delivery infrastructure. Postal is highly scalable and intended for developers and businesses needing reliable email dispatch. -
11
PostfixAdmin
Web based virtual user administration interface for Postfix mail
PostfixAdmin is a web-based interface for managing mail domains, mailboxes, and aliases for Postfix mail servers. It allows administrators to add and configure virtual domains and email users easily, supporting MySQL, PostgreSQL, and SQLite as backend databases. It's widely used in self-hosted email setups for simplifying email management. -
12
Zentyal, Linux Small Business Server
Zentyal is a Linux Small Business Server
Zentyal Server is an easy to use and affordable Linux server, specially designed to meet the needs of small and medium businesses Thanks to Zentyal's Samba integration, Zentyal provides native compatibility with Microsoft Active Directory, allowing you to join Microsoft clients to a domain and manage them easily. Zentyal Server incorporates all the network services required in a small and medium business environment: * Directory & Domain Server with native compatibility with Microsoft Active Directory * Mail Server with ActiveSync and webmail * Gateway with firewall and proxy * Infrastructure Server with DNS/DHCP server, Certification Authority and Virtual Private Networks For more information and download, please access the project's home page. -
13
Inbucket
Disposable webmail server (similar to Mailinator) with built in SMTP
Inbucket is an email testing application; it will accept messages from any email address and make them available to view via a web interface. When you need to test your webapp's outbound emails with Mailinator but are stuck behind a firewall, Inbucket provides the solution. It allows you to keep your new application development secret until it's time to release it. Inbucket is ideal for validating that emails go out as part of your integration test suite, sending links to coworkers to demonstrate an email without sharing your Gmail password, and load testing your application without overwhelming your corporate Exchange server. You can use production data in your test environment without the risk of test messages leaking to an end user, and preview emails in multiple desktop email clients. Use Inbucket for all these needs and more. -
14
Mail-in-a-Box
Take back control of your email with this mail server in a box
Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server, a mail server 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. Our goals are to make deploying a good mail server easy, promote decentralization, innovation, and privacy on the web, have automated, auditable, and idempotent configuration, not make a totally unhackable, NSA-proof server, and not make something customizable by power users. Mail-in-a-Box turns a fresh Ubuntu 18.04 LTS 64-bit machine into a working mail server by installing and configuring various components. It is a one-click email appliance. There are no user-configurable setup options. It "just works." -
15
MailSlurper
Local, web-based mail server application. Slurp mails into oblivion!
MailSlurper is a small SMTP mail server that slurps mail into oblivion! MailSlurper is perfect for individual developers or small teams writing mail-enabled applications that wish to test email functionality without the risk or hassle of installing and configuring a full-blown email server. It's simple to use! Simply set up MailSlurper, configure your code and/or application server to send mail through the address where MailSlurper is running, and start sending emails! MailSlurper will capture those emails into a database for you to view at your leisure. The following are general instructions for compiling MailSlurper. Your details may vary a bit here and there. The below example is based on a Unix-style system, such as Ubuntu or OSX. Furthermore, for instructional purposes, it is assumed that your GOPATH is set to ~/code/go, and that you have a folder in your source directory called github.com. Your setup may vary. -
16
Simscan enables qmail to reject viruses, spam, and block attachments during the SMTP conversation so the email never makes it into your email server. Supports ClamAV, SpamAssassin, DSpam and other virus scanners. Very efficient and written in C.
-
17
NethServer
Linux for for small offices and medium enterprises
NethServer 7 is an operating system for Linux enthusiasts, designed for small offices and medium enterprises. Based on CentOS, the product's main feature is a modular design which makes it simple to turn the distribution into a mail server and filter, web server, groupware, firewall, web filter, IPS/IDS or VPN server. A comprehensive web-based user interface simplifies common administration tasks and enables single-click installation of several pre-configured modules. Stay tuned with NethServer 8! Follow the links on http://www.nethserver.org for more information -
18
Convert Webmail to POP3.Is also included a SMTP/POP3 tunneling system that allow send and receive email in a private network HTTP PROXY based. All connection are plugin based. Over 450 email server supported and tested, GMAIL POP3/SMTP over Proxy Network.
-
19
Small HTTP server
Universal server
It is not only a web server, it is also Mail server, DNS server, FTP server, TFTP server, Proxy server, VPN server and client... All in one! This program will help you to open all the possibilities Internet can offer for your company - public site, provide Internet access and personal mailboxes for each employee! HTTP server. Server Side Includes. Regular expression in SSI. CGI interface for scripts (Executable files; Perl,PHP, or another external interpreters) ISAPI interface. Virtual hosts and directories Mail POP3 server. SMTP server. FTP server HTTP proxy server DNS server DHCP server HTTP TLS VPN server -
20
MailCleaner
Anti Spam SMTP Gateway
MailCleaner Open Source Edition is now discontinued but will continue under the spamtagger project https://github.com/SpamTagger [antispam] MailCleaner is an anti-spam / anti-virus filter SMTP gateway with user and admin web interfaces, quarantine, multi-domains, multi-templates, multi-languages. Using Bayes, RBLs, Spamassassin, MailScanner, ClamAV. Based on Debian. Enterprise ready. MailCleaner is an anti spam gateway installed between your mail infrastructure and the Internet. It includes a complete GNU/Linux OS and a graphical web interface for user and administrative access. It comes in the form of virtual machine templates.. - fully compatible with any SMTP mail server (Exchange, Zimbra, O365,...) -
21
DKIMproxy is an SMTP-proxy that implements the DKIM and DomainKeys standards, to sign and verify email messages using digital signatures and DNS records. It can be used to add DKIM support to nearly any existing SMTP mail server.
-
22
YPOPs! is an application which emulates a POP3/SMTP mail server and provides free POP3 and SMTP access to Yahoo! Mail. It does not depend on Yahoo's POP3/SMTP mail server. You can use a mail client of your choice!
-
23
SmartSieve is a web based graphical user interface for creating and managing sieve scripts for mail filtering and vacation messaging on a cyrus imap mail server. Written in PHP, SmartSieve is easy to configure and use.
-
24
Filebench
File system benchmark
Filebench is a file system and storage benchmark that can generate both micro- and macro-workloads. It employs versatile Workload Model Language (WML) for detailed workload specification. Filebench includes several popular macro-workloads in its distribution: Web-server, Mail-server, Database-server, and others. -
25
Highly scalable/configurable Messaging Platform allowing users in a domain to be distributed on multiple hosts, has multiple queues. Provides virtual domains/users in MySQL. Modern MSP class qmail replacement with ESMTP, POP3/IMAP, QMTP, QMQP support
