FakeSMTP is a Free Fake SMTP Server with GUI for testing emails in applications easily. It is written in Java.
Configure your application to use
localhost as your SMTP server, and all
emails will be intercepted and displayed in this software.
FakeSMTP uses SubEthaSMTP: an easy-to-use server-side SMTP library for Java.
FakeSMTP is free to use for commercial and non-commercial projects and the source code is provided.
It is licensed under the very free BSD or GPL license, whichever you prefer.
You need Java JVM 1.6 or newer installed on your machine.
If you are on a "Unix-like" machine (Mac, GNU/Linux, BSD...), you may have
to be "root" to start the port
25, otherwise, try another port >=
The fakeSMTP.jar is auto-executable. If your desktop environment supports it, you can directly double click on the .jar file. Otherwise, run the following command:
java -jar fakeSMTP-VERSION.jar
If you want to specify the directory where emails will be saved when starting the application, you can use the
java -jar fakeSMTP-VERSION.jar -o output_directory_name java -jar fakeSMTP-VERSION.jar --output-dir output_directory_name
If you want to autostart the SMTP server at launch, you can use the
java -jar fakeSMTP-VERSION.jar -s java -jar fakeSMTP-VERSION.jar --start-server
If you want to autostart the SMTP server without a GUI (background) on a different port and bound to the loopback address:
java -jar fakeSMTP-VERSION.jar -s -b -p 2525 -a 127.0.0.1 java -jar fakeSMTP-VERSION.jar --start-server --background --port 2525 --bind-address 127.0.0.1
If you don't need to save emails on the filesystem (to improve the overall performances), you can use the
-m (memory mode) argument:
java -jar fakeSMTP-VERSION.jar -m
To see all the available options (relay domains, custom eml-viewer...):
java -jar fakeSMTP-VERSION.jar --help
FakeSMTP was created because we couldn't find any free (as in freedom) and cross-platform SMTP server with GUI for testing emails in applications or websites. Listed below are some greats alternatives to Fake SMTP:
- Nice features;
- Open source;
- Windows only (written in .Net).
- Closed source;
- Cross-Platform (written in Java 1.4).
You need to download and setup Maven. Once installed, go to project directory and run the following command:
mvn package -Dmaven.test.skip
This command will create an executable jar on the target folder.
We recommend you not to skip unit tests.
Once you know how to configure unit tests for this project, stop skipping them.
Running integration tests
To run integration tests, you will first need to launch the application
and start the server on port
java -jar fakeSMTP-VERSION.jar -p 2525 -s
You can then run the following command:
Change the default port for unit/integration tests
You need to modify the following file:
Please note that it is better to have two different ports for unit and integrations tests, to avoid any port binding exception while running Maven's
Usage on Docker
Run distributed version: Dockerfile
docker build -t="mail" github.com/Nilhcem/FakeSMTP
docker run -ti -p 250:25 --privileged=true -v /mail:/output mail
Build from source
Get sources from GitHub: Dockerfile
git clone https://github.com/Nilhcem/FakeSMTP cd FakeSMTP
Build the docker image
mvn package docker:build -DskipTests
Run the docker image
docker run -ti -d fakesmtp
Map the SMTP port 25 to host:
Map volume for received mails:
--privileged=true -v /mail-data:/output
- Foward fakesmtp:25 to host port 250,
mount host folder /home/fakesmtp/mail as container folder /output
docker run -ti -d -p 250:25 --privileged=true -v /home/fakesmtp/mail:/output fakesmtp
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