Description
smtp4dev is a fake SMTP server for development and testing. It listens on a local SMTP port, accepts every message your application sends, delivers none of them, and keeps them in a built-in web interface for you to look at.
It solves a very practical problem during development: you need to check what the signup confirmation, the password reset and the billing notice actually look like, without any of them reaching a real inbox. Point your application’s SMTP settings at it and send as many as you like to any address at all, then open the interface to see how the HTML rendered and whether the attachment came through.
Catches everything: Any recipient and any volume is accepted, and nothing is actually delivered, so testing cannot accidentally mail a real person.
Web inbox: The received messages list opens in a browser, where you can read the body, see the HTML rendering, check the plain-text alternative and open attachments.
Raw message view: The source and the MIME structure are visible directly, which is the quickest way to track down an encoding, header or multipart problem.
SMTP session log: Each delivery’s SMTP conversation is recorded — what the client sent and how the server answered — laid out plainly.
Optional relaying: When one particular message does need to go out for real, an upstream server can be configured and the message relayed by hand.
Cross-platform: It runs on Windows, Linux and macOS, and a container image is available for dropping into a development environment.
It solves a very practical problem during development: you need to check what the signup confirmation, the password reset and the billing notice actually look like, without any of them reaching a real inbox. Point your application’s SMTP settings at it and send as many as you like to any address at all, then open the interface to see how the HTML rendered and whether the attachment came through.
Features
Catches everything: Any recipient and any volume is accepted, and nothing is actually delivered, so testing cannot accidentally mail a real person.
Web inbox: The received messages list opens in a browser, where you can read the body, see the HTML rendering, check the plain-text alternative and open attachments.
Raw message view: The source and the MIME structure are visible directly, which is the quickest way to track down an encoding, header or multipart problem.
SMTP session log: Each delivery’s SMTP conversation is recorded — what the client sent and how the server answered — laid out plainly.
Optional relaying: When one particular message does need to go out for real, an upstream server can be configured and the message relayed by hand.
Cross-platform: It runs on Windows, Linux and macOS, and a container image is available for dropping into a development environment.
