How to install Open Webmail 3.00 on Ubuntu 26.04 LTS
====================================================
By Thomas Chung <tchung@openwebmail.org>
Last Update 2026.06.19

Note: Commands prefixed with # are run as root. On Ubuntu you can either run
      "sudo -i" first, or prefix each command with "sudo".

## Ubuntu 26.04 LTS Release Info

2026.04.23 - Ubuntu 26.04 LTS released (will be supported until *April 2036* with Ubuntu Pro / ESM)
             https://lists.ubuntu.com/archives/ubuntu-announce/2026-April/000323.html

## iPhone / Mobile Device Support

Open Webmail 3.00 includes built-in mobile UI support for iPhone, iPad, and Android devices.
When a mobile browser is detected, optimized responsive templates are automatically served
while the desktop UI remains unchanged.

Mobile-optimized views include:
- Login page (touch-friendly inputs and buttons)
- Inbox / folder view (responsive toolbar and message list)
- Read message view (HTML emails fit within viewport)
- Compose / reply view (properly sized fields and buttons)

No additional configuration is required. Mobile support works out of the box.


0) AppArmor and firewall
Ubuntu uses AppArmor instead of SELinux. The apache2 package ships unconfined,
so there is nothing to disable -- no equivalent of "setenforce 0" is needed.

If the ufw firewall is enabled, allow smtp (25), http (80), and https (443):
# ufw allow 25,80,443/tcp
# ufw status

1) Install and Configure postfix and apache2
## Install postfix if not installed
# apt -y install postfix
(when prompted, choose "Internet Site" and set the system mail name)
# systemctl enable --now postfix

!!! WARNING !!!
There may be a restriction for outgoing mail (SMTP port 25) by your ISP/Cloud Provider.
Please check with them if you're not able to send mail due to their restriction.
You can check with a simple telnet test to confirm:
$ telnet remotehost 25
Trying {ip_address_of_remotehost}...

Also you need to check the following parameter to accept incoming mail:
# postconf inet_interfaces
inet_interfaces = all

If you see localhost, set it to all and restart postfix:
# postconf -e "inet_interfaces = all"
# systemctl restart postfix

## Install apache2 if not installed
# apt -y install apache2
# systemctl enable --now apache2

## Enable the CGI module (required by openwebmail)
# a2enmod cgid

## (Optional) Enable HTTPS
# a2enmod ssl
# a2ensite default-ssl
# systemctl restart apache2

2) Configure openwebmail apt repository for ubuntu26
# apt -y install ca-certificates wget
# wget -O /usr/share/keyrings/openwebmail.gpg https://openwebmail.org/repo/ubuntu26/openwebmail.gpg
# echo "deb [signed-by=/usr/share/keyrings/openwebmail.gpg] https://openwebmail.org/repo/ubuntu26 ./" > /etc/apt/sources.list.d/openwebmail.list
# apt update

3) Install openwebmail pkgs for ubuntu26
# apt -y install openwebmail
(this will also install the required perl dependency packages and openwebmail-data)

The package automatically enables the openwebmail apache2 config, turns on the
cgid module, and restarts apache2.

4) Run openwebmail-tool to initialize
# /usr/local/bin/openwebmail-tool --init --yes
(--init creates the initial files and directories needed for openwebmail)
(--yes will automatically send a site report to the developer)

5) Open a Browser and login to webmail URL with non-root user account
https://{hostname}/webmail

If you see the Open Webmail Login, you've installed successfully!


## Alternative: install from the downloaded .deb files (no apt repository)

If you have the two .deb files instead of using the apt repository:
# apt -y install ./openwebmail_3.00-1_amd64.deb ./openwebmail-data_3.00-1_all.deb
(apt resolves and installs the perl dependencies automatically)
# /usr/local/bin/openwebmail-tool --init --yes


## Notes / Troubleshooting

* Web service is "apache2" (running as user www-data) -- not "httpd"/"apache".

* If the browser shows "503 Service Unavailable" right after install, the
  mod_cgid helper daemon needs a full restart (a graceful reload is not enough):
  # systemctl restart apache2

* /etc/shadow on Ubuntu uses yescrypt ($y$) password hashing. Login works out of
  the box; when a user changes their password it is re-hashed as SHA-512 ($6$),
  which Ubuntu also accepts.

* If openwebmail complains that openwebmail.pl must be setuid root, run:
  # /usr/local/bin/openwebmail-tool --fix

* For virus scanning, install clamav-daemon and set enable_viruscheck in
  /var/www/cgi-bin/openwebmail/etc/openwebmail.conf