email: Tweak client auto-configuration file

- Allow STARTTLS as it is safe to do so.

- Allow POP service in the event user wants to keep the mails on the server.

- Add documentation link (this is currently unused and for documenting the code
only).

- Allow translation of display name and short name.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/email/templates/email-autoconfig.xml

@@ -1,9 +1,15 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
+{% comment %}
+# SPDX-License-Identifier: AGPL-3.0-or-later
+{% endcomment %}
+
+{% load i18n %}
+
 <clientConfig version="1.1">
   <emailProvider id="{{ host }}">
     <domain>{{ host }}</domain>
-    <displayName>FreedomBox Mail</displayName>
-    <displayShortName>FBXMail</displayShortName>
+    <displayName>{% trans "FreedomBox Email" %}</displayName>
+    <displayShortName>{{ box_name }}</displayShortName>
     <incomingServer type="imap">
       <hostname>{{ host }}</hostname>
       <port>993</port>
@@ -11,6 +17,13 @@
       <username>%EMAILLOCALPART%</username>
       <authentication>password-cleartext</authentication>
     </incomingServer>
+    <incomingServer type="pop3">
+      <hostname>{{ host }}</hostname>
+      <port>995</port>
+      <socketType>SSL</socketType>
+      <username>%EMAILLOCALPART%</username>
+      <authentication>password-cleartext</authentication>
+    </incomingServer>
     <outgoingServer type="smtp">
       <hostname>{{ host }}</hostname>
       <port>465</port>
@@ -18,5 +31,15 @@
       <username>%EMAILLOCALPART%</username>
       <authentication>password-cleartext</authentication>
     </outgoingServer>
+    <outgoingServer type="smtp">
+      <hostname>{{ host }}</hostname>
+      <port>587</port>
+      <socketType>SSL</socketType>
+      <username>%EMAILLOCALPART%</username>
+      <authentication>password-cleartext</authentication>
+    </outgoingServer>
+    <documentation url="https://wiki.debian.org/FreedomBox/Manual/Email">
+      <descr lang="en">FreedomBox Manual</descr>
+    </documentation>
   </emailProvider>
 </clientConfig>

plinth/modules/email/views.py

@@ -125,6 +125,10 @@ class AliasView(FormView):
 
 
 class XmlView(TemplateView):
+    """Serve Thunderbird auto-configuration file.
+
+    https://wiki.mozilla.org/Thunderbird:Autoconfiguration:ConfigFileFormat
+    """
     template_name = 'email-autoconfig.xml'
 
     def render_to_response(self, *args, **kwargs):