How to setup debian mail

Setting up a mail server on Debian can be a bit complex, but I'll provide a step-by-step guide to help you get started. We'll be using Postfix as the mail transfer agent (MTA) and Dovecot as the IMAP/POP3 server.

Prerequisites

A Debian system (e.g., Debian 10 or later)
A domain name (e.g., example.com)
A static IP address or a dynamic DNS (DDNS) service
A mail client (e.g., Thunderbird, Outlook) to test the setup

Step 1: Install required packages

Update the package list and install the required packages:

sudo apt update
sudo apt install postfix dovecot-imapd dovecot-pop3d

Step 2: Configure Postfix

Edit the Postfix configuration file:

sudo nano /etc/postfix/main.cf

Add the following lines to the end of the file:

mydestination = example.com
myhostname = mail.example.com
myorigin = $myhostname

Replace example.com with your domain name.

Step 3: Configure Dovecot

Edit the Dovecot configuration file:

sudo nano /etc/dovecot/dovecot.conf

Add the following lines to the end of the file:

mail_location = maildir:~/Maildir
first_valid_uid = 1000
first_valid_gid = 1000

Replace 1000 with the UID and GID of the user you want to use for mail delivery.

Step 4: Create a mail user

Create a new user for mail delivery:

sudo useradd -m -s /bin/false mailuser

Set the password for the mail user:

sudo passwd mailuser

Step 5: Configure Postfix to use Dovecot

Edit the Postfix configuration file again:

sudo nano /etc/postfix/main.cf

Add the following lines to the end of the file:

virtual_transport = dovecot
dovecot_destination_recipient_limit = 1

Step 6: Restart Postfix and Dovecot

Restart the Postfix and Dovecot services:

sudo service postfix restart
sudo service dovecot restart

Step 7: Test the mail setup

Use a mail client to test the setup. You can use the telnet command to test the mail server:

telnet mail.example.com 25

Replace mail.example.com with your mail server's hostname.

Step 8: Configure DNS

Update your DNS records to point to your mail server. You'll need to create the following records:

MX record: mail.example.com with a priority of 10
A record: mail.example.com with the IP address of your mail server
TXT record: v=spf1 a mx ptr?all (optional, but recommended for spam protection)

Step 9: Verify the mail setup

Use a mail client to send and receive emails. You can also use tools like postmap and dovecot-test to test the mail setup.

That's it! You now have a basic mail setup on Debian using Postfix and Dovecot. You can further customize the setup by configuring additional features, such as spam filtering, antivirus scanning, and more.

Mail Knowledge

How to setup debian mail