How to get started
To run PenterepMail, you will need a virtualization tool such as Oracle VirtualBox, Hyper-V, or VMware.
Installation and setup
Start by using the link above to download the latest PenterepMail image and import it into the virtualization tool. After the import is done, you will need to enable and properly configure the network card in the virtual machine. We recommend that you set up your network card in a bridge so that you can test everything also from other devices on the network, for example from your mobile phone. This allows you to attack each other in the team even from multiple computers. Once the virtual machine starts and boots, it will be assigned an IP address, which will be displayed under the welcome banner. At this point, the only thing left to do is to add an entry assigning an IP address to the www.penterepmail.loc domain in the hosts file on the system from which you will connect to PenterepMail, for example:
192.168.1.100 penterepmail.loc www.penterepmail.loc
However, we would rather recommend that you set PenterepMail's IP address straight as your DNS server. You'll then be able to access other web applications running on the same server, or test attacks against DNS-related vulnerabilities.
Anything else?
To make sure you enjoy testing all vulnerabilities 100%, you will need two more virtual machines. One under which you will act as the attacker - we recommend the Kali Linux distribution - and another under which you will act as the victim. On the other machine, you can deploy, for example, Windows or another system that you regularly use. You can also successfully use your main operating system instead of the victim virtual machine.
To test some of the types of attacks, it will definitely be useful if you run your own web server, such as Apache, on the attacker's device. In this case, you will need to own a domain to point to the attacker's server. All you need is a fictitious domain name to which you assign an entry using the hosts file on all machines that will access that domain. Since the PenterepMail virtual server itself will probably need to be able to access your domain, you will also need to edit its hosts file, which is made available at http://www.penterepmail.loc/admin/hosts.php.
Using a mail client
PenterepMail is not just a web application, but a full-fledged mail server that you can also connect to using any mail client such as Outlook or Thunderbird. POP3, IMAP and SMTP protocols are available for connection. If you want to use this option, set up the SMTP/POP3/IMAP server in your mail client to www.penterepmail.loc. The services run on standard ports.
As PenterepMail is a fully featured mail server, you can send messages from it to any email address. However, be aware that these messages will be sent from a non-existent domain (penterepmail.loc) and will therefore likely be treated as spam by the recipient’s system and discarded.
Licences
PenterepMail is and always will be completely free. You can use it free of charge not only for personal purposes, but also for public demonstrations or teaching. The tool is distributed under the MIT licence.