Open Source Mac Email Servers

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!

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.

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.

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

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.

Haraka is a highly scalable node.js email server with a modular plugin architecture. 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 a MSA running on port 587 with auth and dkim_sign plugins enabled. Haraka makes no attempt to be a mail store (like Exchange or Postfix/Exim/Qmail), a LDA, nor 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.

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.

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.

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.

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.

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.

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.

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!

Hedwig is an open source IMAP, SMTP, POP3 server written in Java, designed with ease of installation and configuration in mind. Hedwig enables storage of mail message headers in a relational database(MySQL or Oracle) and mail messages in a file system. Visit http://hwmail.sourceforge.net/ for more information.

PhpXmail the web based management software for the Xmail mail server and GUI of it's administration extensions.

PyWebMail is a Python library and POP3 gateway that enable working with WebMail servers like with POP3 or IMAP mail server. Currently Mail.Com, Yahoo! Mail, Gmail, Netscape.Net, HotMail and some minor servers support is finished.

The attachment grabber reads all emails from an IMAP or POP3 email server, extracts and saves the selected attachments from the emails in a folder on your hard drive or server.

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.

Foedus Mail is a mail server written in Java. The goal is to produce stable IMAP, SMTP, and POP3 support and then to build upon and refine it.

This is an intranet mail server. The project is presently named JMail.

Java based mailserver providing a SMTP and POP3 protocoll implementation easy configurable, OS independent, extendible

A small, fast, secure, anti-spam SMTP mail server (MTA). Delivery to mbox files and Maildirs supported. qwik-smtpd supports RBL, relay checking, raw/custom message handlers, and more. Custom authentication via checkpassword and a qmail-compatible configu

Modest system requirements, decent performance, simple installation and upgrade, no database required - all these make RainLoop Webmail a perfect choice for your email solution.

A web based easy to use interface for creating Sieve scripts on an Cyrus Imapd mail server as well as allowing users to set access controls, create new mailboxes and view their mail quota. Also give administrators full administrative capabilities(quota,ac

acmemail is a multiuser IMAP/POP3 to Web gateway (or webmail program). It reads mail from a mail server and displays it using HTML on a web server. It is written in Perl, has full support for MIME (and mod_perl) and is quite pretty.