How to Install OpenSMTPD on Arch Linux

OpenSMTPD is a free and open-source SMTP server that can be used for sending and receiving emails. Here's how you can install OpenSMTPD on Arch Linux.

Prerequisites

Before you start, make sure that your Arch Linux system is up to date by running the following commands:

sudo pacman -Syu

Installation

Open a terminal on your Arch Linux system.
Install OpenSMTPD by running the following command:
```
sudo pacman -S opensmtpd
```
After the installation is complete, you can start OpenSMTPD by running the following command:
```
sudo systemctl start opensmtpd
```
This will start the OpenSMTPD service on your system.

Verify that OpenSMTPD is running by running the following command:

sudo systemctl status opensmtpd

If the service is running, you should see the following output:

opensmtpd.service - OpenSMTPD SMTP server
Loaded: loaded (/usr/lib/systemd/system/opensmtpd.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2022-01-11 12:00:00 PST; 1h 3min ago

Configuration

After you have installed OpenSMTPD, you will need to configure it to use it as your SMTP server. Here's how you can configure it:

Create a configuration file for OpenSMTPD by running the following command:
```
sudo nano /etc/smtpd/smtpd.conf
```
This will open the smtpd.conf file in the Nano text editor.
Add the following lines to the smtpd.conf file:
```
listen on lo0
listen on smtp bind-to lo0
accept for local relay
```
These lines tell OpenSMTPD to listen on the loopback interface, bind to the loopback interface, and accept local connections for relaying.
Save and close the file.
Restart the OpenSMTPD service to apply the new configuration:
```
sudo systemctl restart opensmtpd
```
You can now use OpenSMTPD as your SMTP server.

Conclusion

OpenSMTPD is a versatile SMTP server that can be used for sending and receiving emails. After following the steps in this tutorial, you should have OpenSMTPD up and running on your Arch Linux system.