Linux / MacOS


Install Stalwart IMAP server by running the following command in your terminal:

curl --proto '=https' --tlsv1.2 -sSf | sudo sh

This command will install Stalwart IMAP under the /usr/local/stalwart-imap folder and start the stalwart-imap service. Please note that root access is required to perform the installation, if you don’t feel comfortable running the install script as root you may also download the latest release and perform a manual installation.

Configure JMAP

In order to use Stalwart IMAP, you need a JMAP server backend such as Stalwart JMAP. To configure the URL of your JMAP server, edit the /usr/local/stalwart-imap/etc/config.yml file and update the jmap-url parameter with the base URL of your JMAP server. For example, if your JMAP server’s hostname is then the jmap-url parameter should look like this:


Setup TLS

It is highly recommended to enable TLS on your IMAP server. If you currently don’t have a TLS certificate, you can obtain one for free from Let’s Encrypt. Once you have your certificate ready, copy your certificate and private key to their default locations as follows:

sudo cp mycert.crt /usr/local/stalwart-imap/etc/imap.crt
sudo cp mykey.key /usr/local/stalwart-imap/etc/imap.key

Restart service

Once you have completed the setup instructions, restart your Stalwart IMAP server:

sudo systemctl restart stalwart-imap

Or, if you are using MacOS:

sudo launchctl kickstart -k stalwart.imap

Important: On Linux systems, in order to be able to listen on the privileged ports 143 and 993, the Stalwart IMAP service needs to run as the root user (this is not the case in MacOS). To run the service as the stalwart-imap user, edit the /etc/systemd/system/stalwart-imap.service file and uncomment the User and Group parameters. Then disable privileged ports with the command sudo sysctl -w net.ipv4.ip_unprivileged_port_start=0 and restart the service. Alternatively, you may also bind Stalwart JMAP to an unprivileged port such as 1143 and then forward the connections using iptables such as iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 143 -j REDIRECT --to-port 1143.

Next Steps

If everything is correct, you should now be able to connect with an IMAP4 client on ports 143 or 993 (TLS).