feat: add postfix config

Author: binarypatrick

_posts/2023-06-26-configuring-postfix-with-gmail.md

@@ -0,0 +1,73 @@
+---
+layout: post
+title: "Configuring Postfix with Gmail"
+date: 2023-06-26 00:00:00 -0400
+category: "Service Setup"
+tags: ['linux', 'email', 'gmail']
+---
+
+Email is often a critical component notification for jobs and other things in linux. This is how I set up [Postfix](https://www.postfix.org/) on most of my instances. This guide is geared towards Debian based distros but can be translated for others.
+
+## Required Software
+
+```bash
+sudo apt install postfix mailutils -y
+```
+
+Both Postfix and mailutils make this much easier
+
+## Configuration
+
+Open the Postfix configuration file:
+
+```bash
+sudo nano /etc/postfix/main.cf
+```
+
+Append the following to the end:
+
+```conf
+relayhost = [smtp.gmail.com]:587
+smtp_sasl_auth_enable = yes
+smtp_sasl_password_maps = hash:/etc/postfix/gmail_credentials
+smtp_sasl_security_options = noanonymous
+smtp_use_tls = yes
+```
+
+Notice that instead of adding your gmail credentials directly, we're adding them to a file named `gmail_credentials`. Your credentials will depend on whether you use multi-factor authentication (MFA/2FA) or not. If you are now, then you can just put your credentials directly into this file, otherwise you'll need to create an app password. It is highly recommended to use multi-factor authentication whenever possible so I'll assume you are.
+
+> It is highly recommended to use multi-factor authentication whenever possible
+{: .prompt-tip }
+
+Go to your [Google account page](https://myaccount.google.com/) and select _Security_ from the side navigation. Then in the center, select _2-Step Verification_. After verifying it's really you, scroll to the bottom and find _App Passwords_. From this page you can generate a new app specific password. I often select custom from the drop down and give it a descriptive name, then select _Generate_.
+
+Remember to copy the generated password, because you will never see it again. Now you can use this new generated password instead of your actual password in your `gmail_credentials` file.
+
+```bash
+sudo nano /etc/postfix/gmail_credentials
+```
+
+```conf
+[smtp.gmail.com]:587 <username>@gmail.com:<password>
+```
+
+Once you have your credentials file created, you need to secure it add enroll it with postfix.
+
+```bash
+sudo chmod 400 /etc/postfix/gmail_credentials
+sudo postmap /etc/postfix/gmail_credentials
+```
+
+Now you can reload the Postfix service
+
+```bash
+sudo systemctl reload postfix
+```
+
+## Testing
+
+Once reloaded, you should be able to send email from the CLI
+
+```bash
+echo "This is a test email" | mail -s "Test of Postfix using Gmail" <your@email.address>
+```