Dovecot is a secure, open-source IMAP and POP3 server that works alongside Postfix to deliver email to mail clients. This guide installs and configures Dovecot IMAP on Ubuntu 24.04 LTS.

Tested and valid on:

  • Ubuntu 24.04 LTS

Prerequisites

  • Ubuntu 24.04 LTS server
  • Postfix installed and configured
  • A domain name with MX records
  • A user with sudo privileges

Step 1 – Install Dovecot

Install Dovecot with IMAP and LMTP support:

sudo apt update
sudo apt install dovecot-core dovecot-imapd dovecot-lmtpd -y

Step 2 – Configure Dovecot Mail Location

Edit the main Dovecot config:

sudo nano /etc/dovecot/dovecot.conf

Set the mail location:

mail_location = maildir:~/Maildir

Step 3 – Configure Authentication

Edit the auth config:

sudo nano /etc/dovecot/conf.d/10-auth.conf

Set:

disable_plaintext_auth = yes
auth_mechanisms = plain login

Step 4 – Configure the Mailbox

Edit the mail config:

sudo nano /etc/dovecot/conf.d/10-mail.conf

Set:

mail_location = maildir:~/Maildir

Step 5 – Configure SSL

Enable SSL for IMAP:

sudo nano /etc/dovecot/conf.d/10-ssl.conf

Set:

ssl = required
ssl_cert = </etc/ssl/certs/mysite.crt
ssl_key = </etc/ssl/private/mysite.key

Step 6 – Configure Postfix to Use Dovecot LMTP

Edit /etc/postfix/main.cf:

mailbox_transport = lmtp:unix:private/dovecot-lmtp

Edit /etc/dovecot/conf.d/10-master.conf to enable the LMTP socket for Postfix.

Step 7 – Restart and Test

Restart both services:

sudo systemctl restart dovecot postfix

Test IMAP connectivity:

openssl s_client -connect localhost:993

Conclusion

Dovecot is now handling IMAP delivery on Ubuntu 24.04 LTS. Users can connect with email clients like Thunderbird or Apple Mail using IMAP with SSL/TLS on port 993.