Outlook autodiscover with nginx

Reimplementation of Outlook's autodiscover protocol with PHP working with NGINX.

Requirements

• NGINX webserver
• PHP (with an installed XML module)

Installation

1. Clone this repository (e.g. into the /var/www/ directory)
2. Edit the config.xml file to suit your mailserver
3. Create the following DNS records (instead of example.com use your own domain):

Essential records:
  autoconfig.example.com		A	<ip of your server>
  _autodiscover._tcp.example.com	SRV 10	10 443 autoconfig.example.com.

Optional recommended records:
  _imaps._tcp.example.com		SRV 0	1 993 <your mailserver's subdomain>
  _submission._tcp.example.com		SRV 0	1 587 <your mailserver's subdomain>

4. Create a new NGINX virtual host and insert the correct paths, server name and PHP socket:

server {
        listen 443 ssl http2;
        listen [::]:443;

        root /path/to/the/repo;
        server_name autoconfig.example.com;

        ssl_certificate /path/to/the/certificate;
        ssl_certificate_key /path/to/the/key;

        location ~* ^/Autodiscover/Autodiscover.xml {
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass unix:/var/run/php/php7.3-fpm.sock; # change to your PHP socket
            include /etc/nginx/fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            try_files /autodiscover-xml.php =404;
          }

        location ~* ^/Autodiscover/Autodiscover.json {
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass unix:/var/run/php/php7.3-fpm.sock; # change to your PHP socket
            include /etc/nginx/fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            try_files /autodiscover-json.php =404;
        }
}

5. Reload NGINX: nginx -s reload
6. Done! You can check if everything is correct here or by doing a right click while holding CTRL on the Outlook icon in the taskbar and selecting "Email-Autodiscover test"

Thunderbird autoconfig

This project also supports Thunderbird autoconfig. To activate it you have to add the following into the server block of the upper mentioned virtual host and change the PHP socket:

        location ~* ^/mail/config-v1.1.xml {
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass unix:/var/run/php/php7.3-fpm.sock; # change to your PHP socket
            include /etc/nginx/fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            try_files /autoconfig.php =404;
        }

And then reload NGINX: nginx -s reload

Other

Some older versions of Outlook may use the so-called Guesssmart which basically tries every possible POP3, IMAP and SMTP combination to find the correct settings. This creates a lot of requests to the server, so please beware that you might have to adjust some anti-spam or anti-brute-force mechanisms on your server (e.g. fail2ban, ...).

License

This project is licensed under the GNU General Public License Version 3 - see the LICENSE file for details.