MailCatcher - Catches mail and serves it through a dream

•    Ruby

---

MailCatcher runs a super simple SMTP server which catches any message sent to it to display in a web interface. Run mailcatcher, set your favourite app to deliver to smtp://127.0.0.1:1025 instead of your default SMTP server, then check out http://127.0.0.1:1080 to see the mail that's arrived so far.

smtp-server smtp mail-server smtp-sink test-framework testing-tool test-mail-server

magento2-gmail-smtp-app - Configure Magento 2 to send email using Google App, Gmail, Amazon Simple Email Service (SES), Microsoft Office365 and many other SMTP (Simple Mail Transfer Protocol) servers

•    PHP

---

Configure Magento 2 to send all transactional email using Google App, Gmail, Amazon Simple Email Service (SES), Microsoft Office365 or other SMTP server. Sending transactional emails to customers is a vital part of running an e-commerce store. Our free custom Magento extension integrates with all major email service provider and third-party SMTP server to reliably deliver messages in customers' inbox.

magento-2 magento2-extension gmail-smtp gmail ses smtp smtp-server magento custom-smtp office365 amazon-ses amazon mailgun mandrill hotmail sendgrid email elastic-email mailchimp mailserver

James - Enterprise Mail Server

•    Java

---

James (a.k.a Java Apache Mail Enterprise Server) is a 100% pure Java SMTP and POP3 Mail server, and NNTP News server designed to be a complete and portable enterprise mail/messaging engine solution based on currently available open messaging protocols.

mail-server email-server enterprise mailing-list smtp lmtp pop3 nntp imap mta mail-delivery-agent

Papercut - Papercut Simple Desktop SMTP Server

•    Javascript

---

Ever need to test emails from an application or web site but don't want them accidently being sent or having to deal with the hassle of setting up a test email server? Papercut is a quick email viewer with a built-in SMTP server designed to only receive messages. It doesn't enforce any restrictions how you send your email. It allows you to view the whole email-chilada: body, html, headers, attachment down to the naughty raw bits. It can be set to run on startup and sits quietly minimized in the tray giving you a balloon popup when a new message arrives.Download Papercut.Setup.exe installer.

papercut smtp-server smtp testing server

Mail-in-a-Box - One click easy-to-deploy SMTP server

•    Python

---

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.

smtp email mail server smtp-server mail-server spf dkim dmarc spam-filtering

C# Email Server - SMTP and POP3 Email Server in CSharp

•    CSharp

---

C# Email Server (CES). Implements SMTP and POP3 components that can be used as a standalone server or as components in other applications. It is a port of the Java Email Server (JES). This component allows a program to accept incoming emails and process them using user defined logic.

smtp-server smtp pop3 mail-server email-server email

MailSlurper - Local, web-based mail server application. Slurp mails into oblivion!

•    Go

---

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.

email-server mail-server smtp

Mailias

•    

---

Mailias makes testing of email enabled applications easier for DEVs and QAs. You no longer need to have multiple "real" email addresses to test and validate registration and notification features. You can alias many email address and have your own Mailias. Written in C# thi...

alias development-tool email-management email-server mail-server smtp smtp-server

greenmail - Official master for the Greenmail project

•    Java

---

GreenMail is an open source, intuitive and easy-to-use test suite of email servers for testing purposes. Supports SMTP, POP3, IMAP with SSL socket support. GreenMail also provides a JBoss GreenMail Service. GreenMail is the first and only library that offers a test framework for both receiving and retrieving emails from Java.

mail-server email-server test-mail-server test-framework testing-tool sandbox

Citadel

•    C

---

Citadel is a collaboration suite (messaging and groupware). It provides support for Email, Calendaring/Scheduling, Address books, Bulletin boards, Mailing List Server, Instant Messaging, Wiki, Multiple domain support.

mail-server groupware bulletin-board mailing-list wiki instant-messaging smtp pop3

MailDev - :mailbox: SMTP Server + Web Interface for viewing and testing emails during development.

•    Javascript

---

MailDev is a simple way to test your project's generated emails during development with an easy to use web interface that runs on your machine built on top of Node.js. If you want to use MailDev with Docker, you can use the djfarrelly/maildev image on Docker Hub. For a guide for usage with Docker, checkout the docs.

maildev smtp nodemailer docker smtp-server mailcatcher testing development developer-tools email e-mail mail

JavaMail - Java library to build Mail and Messaging Applications

•    Java

---

The JavaMail API is a set of abstract APIs that model a mail system. The API provides a platform independent and protocol independent framework to build Java technology based email client applications. The JavaMail API provides facilities for reading and sending email. Service providers implement particular protocols. Several service providers are included with the JavaMail API package; others are available separately.

email-library mail-library smtp-library pop3-library imap-library mail smtp imap pop3

CRSMail - JAVA based E-Mail server

•    Java

---

CRSMail a 100% JAVA based E-Mail server. It supports SMTP, POP3, Plugins, Can listen on multiple ports, Log's everything to a log file etc.

smtp-server smtp pop3 mail-server email-server email

Java Email Server

•    Java

---

JES is a multi-featured hybrid MTA/MDA server written in the java programming language. It supports TLS, SSL, SMTP authentication, spam control and lot more.

smtp-server smtp pop3 mail-server email-server email

Mock SMTP Server

•    

---

The Mock SMTP Server is a simple email server that only displays each email message it receives in the application window. It is intented to test applications that send email. It will not store or relay email. Only the minimum requirements of RFC 5321 are implemented.

mock server smtp

MXRecordLookup

•    

---

Now that Vista and above no longer includes a SMTP server it has made things harder for developers to test SMTP client code. That's where this steps in. Send the email directly to the SMTP server assigned to that email address by querying its MX record.

email mx-record smtp vista

Hedwig - Send email to any SMTP server like a boss, in Swift and cross-platform

•    Swift

---

Hedwig is a Swift package which supplies a set of high level APIs to allow you sending email to an SMTP server easily. If you are planning to send emails from your next amazing Swift server app, Hedwig might be a good choice. You can find more information on how to use Swift Package Manager in Apple's official page.

mail smtp cross-platform server

go-guerrilla - Mini SMTP server written in golang

•    Go

---

Breaking change: The structure of the config has recently changed to accommodate more advanced TLS settings. A lightweight SMTP server written in Go, made for receiving large volumes of mail. To be used as a package in your Go project, or as a stand-alone daemon by running the "guerrillad" binary.

smtp-server server smtp mda mail-delivery-agent

Enkive - Email Archiving and eDiscovery software

•    Java

---

Enkive is a e-mail archiving and retrieval application. It captures e-mail messages as they arrive or are sent to ensure they are retained before a worker can delete them in an e-mail client. The archived mails could be searched and retrieved. Enkive can import mail from a file in mbox format. It dedupicates email and attachments, only one copy of the messages are stored.

mail email-archiving archive ediscovery

smtp-validate-email - A PHP class for performing email addresses validation via SMTP

•    PHP

---

Perform email address validation/verification via SMTP. The SMTPValidateEmail\Validator class retrieves MX records for the email domain and then connects to the domain's SMTP server to try figuring out if the address really exists.

smtp email-validation