Internal mail server with postfix and dovecot

Mon, 23 Feb 2026 00:00:00 +0000

I need an internal mail server (it will not be open to the outside world) to receive posts from the infrastructure in general, router switch, or backup reports. We will do this with Postfix and Dovecot on Ubuntu 24.04. The emails are intended for an existing AD user.

1. Join the server to the Active Directory domain with SSSD

Install the necessary packages

sudo apt update
sudo apt install realmd sssd sssd-tools adcli samba-common-bin libnss-sss libpam-sss

Discover and join the domain

# Check that the domain is accessible
realm discover mydomain.local

# Join the domain (an AD account with sufficient rights is required)
sudo realm join --user=Administrator mydomain.local

Check the join

realm list

You should see something like:

Postfix on Aperture Zone

Internal mail server with postfix and dovecot

1. Join the server to the Active Directory domain with SSSD

Install the necessary packages

Discover and join the domain

Check the join