Add a guide to use Thunderbird through Tor

src/docs/anon/tor.en.md

@@ -52,3 +52,132 @@ If you feel more old-fashioned, you can also find a list of public proxies here:
 - <http://www.freeproxy.ru/en/free_proxy/>
 - <http://www.samair.ru/proxy/>
 
+
+Configuring Thunderbird to send and receive email via Tor
+---------------------------------------------------------
+
+#### **Context**
+
+While this approach is not recommended by torproject, here we provide a few steps to use Tor to communicate with our mailservers.
+This might be a good option in situations where one is not able to access our mailservers directly (for example because of state censorship).
+
+#### **Prerequisite 1: having a running Tor instance on your computer**
+
+Tor is a program that exposes a local proxy to connect to the internet (and also to the network of hidden services). Tor Browser is a
+modified flavour of Firefox, crafted to work better with the Tor proxy. It ships with a working Tor proxy. Whenever you turn on Tor Browser,
+a local instance of Tor proxy is started.
+Nevertheless, you can run Tor proxy independently from the Tor Browser. If you are able to do so, go ahead. Otherwise, to use Thunderbird through
+Tor, you will need to first start Tor Browser.
+
+#### **Prerequisite 2: configure the account**
+
+First of all, you need a working Autistici/Inventati email account (if you are not able to access directly our mailservers, and did not verify
+if the account is working, just go ahead).
+Let us add a new account, click on the main menu, then select `New`, and then `Existing Mail Account...`
+
+![](/static/img/man_mail_tor/en/00_create_new_1.png)
+![](/static/img/man_mail_tor/en/00_create_new_2.png)
+
+Then you will be prompt with a box, where you can put the name you want to display, the email and the password.
+
+![](/static/img/man_mail_tor/en/01_new_account.png)
+
+Clicking on `Continue` will trigger Thunderbird to search for the mailserver. In case of success the box will appear like this
+
+![](/static/img/man_mail_tor/en/02_new_account_server_data.png)
+
+If the mailservers are not retrieved, just insert these parameters
+
+<table class="table">
+    <thead>
+        <tr>
+            <th scope="col" style="text-align: center">protocol</th>
+            <th scope="col" style="text-align: center">server</th>
+            <th scope="col" style="text-align: center">port</th>
+            <th scope="col" style="text-align: center">SSL</th>
+            <th scope="col" style="text-align: center">authentication</th>
+        </tr>
+    </thead>
+    <tbody>
+        <tr>
+            <td scope="col" style="text-align: center">IMAP</th>
+            <td scope="col" style="text-align: center">mail.autistici.org</th>
+            <td scope="col" style="text-align: center">485</th>
+            <td scope="col" style="text-align: center">STARTTLS</th>
+            <td scope="col" style="text-align: center">Normal password</th>
+        </tr>
+        <tr>
+            <td scope="col" style="text-align: center">SMTP</th>
+            <td scope="col" style="text-align: center">smtp.autistici.org</th>
+            <td scope="col" style="text-align: center">587</th>
+            <td scope="col" style="text-align: center">STARTTLS</th>
+            <td scope="col" style="text-align: center">Normal password</th>
+        </tr>
+    </tbody>
+</table>
+
+and modify the username to insert your **full email**, clicking on `Manual config`.
+
+![](/static/img/man_mail_tor/en/03_new_account_fix_username.png)
+
+#### **Configure Thunderbird to use Tor as proxy**
+
+Now you should have configured Thunderbird with your A/I account.
+
+![](/static/img/man_mail_tor/en/04_new_account_folders.png)
+
+Let's modify how Thunderbird connects to the server. Rembember that this is a **global configuration**: **every account** you have on Thunderbird
+will be used **through Tor**. Go to the menu, then select `Preferences`, and then again `Preferences`.
+
+![](/static/img/man_mail_tor/en/09_network_settings_1.png)
+![](/static/img/man_mail_tor/en/09_network_settings_2.png)
+
+In the new windox, select `Advanced` in the left column, then click on the `Network & Disk Space` tab.
+
+![](/static/img/man_mail_tor/en/09_network_settings_3.png)
+
+On that tab, click `Settings` in the `Connection` section. In the new window, select `Manual proxy configuration` and enter
+the `127.0.0.1` in the `SOCKS Host` field and, on the same row, `9050` in the `Port` field. Select also `SOCKS v5` below.
+Make also sure to tick the `Proxy DNS when using SOCKS v5` box.
+
+![](/static/img/man_mail_tor/en/10_network_settings_box.png)
+
+#### **Insert the A/I hidden service as mail server**
+
+This last step is not mandatory, but is recommended. Instead of using the aforementioned addresses to connect to the A/I mailservers,
+you should use the hidden service version. Indeed, this will connect you to the very same server, but because of how Tor works, its safer
+to use the hidden service instead of the ordinary one.
+
+Let's first modify the IMAP server address. Let's right click on the A/I account in the left column. From the drop down menu, select
+`Settings`.
+
+![](/static/img/man_mail_tor/en/05_modify_settings.png)
+
+In the newly opened window, go to `Server Settings`, second entry from above. There, replace `mail.autistici.org` in the `Server Name` field
+with `autinv5q6en4gpf4.onion`. Then, click `Ok` in the bottom right.
+
+To replace the SMTP server address, go to the very last voice in the left column, `Outgoing Server (SMTP)`.
+
+![](/static/img/man_mail_tor/en/06_server_settings.png)
+
+There, select the `smtp.autistici.org` entry in the box and click `Edit`.
+
+![](/static/img/man_mail_tor/en/07_outgoing_server_settings.png)
+
+In the new window, replace `smtp.autistici.org` in the `Server Name` field with `autinv5q6en4gpf4.onion`
+
+![](/static/img/man_mail_tor/en/08_outgoing_server_settings_box.png)
+
+**BEWARE**: the next time you will retrieve the email from the webserver AND the very first time you will send an email using these new configurations,
+you will be prompted with an error message like these
+
+![](/static/img/man_mail_tor/en/11_accept_smtp_certificate.png)
+![](/static/img/man_mail_tor/en/12_accept_imap_certificate.png)
+
+**THIS IS RIGHT**, the mailservers still present to you a TLS certificate, but the name of such certificate DOES NOT MATCH the hidden service.
+You can safely click on `Confirm Security Exception`, having `Permanently store this exception` flagged. If you want, you can verify that this certificates
+bear the ordinary name (i.e. `mail.autistici.org` for IMAP and `smtp.autistici.org` for SMTP). If you do not accept these _invalid_ certificates, you won't
+be able to use our email through Tor. You will need to repeat this operation about every 3 months (such is the validity span of our certificates: we renew
+them with such frequency).
+
+![](/static/img/man_mail_tor/en/11_certificate_view.png)