implement Mozilla (e.g. Thunderbird) autoconfiguration file

fixes #241

conf/mozilla-autoconfig.xml

+<?xml version="1.0"?>
+<clientConfig version="1.1">
+    <emailProvider id="PRIMARY_HOSTNAME">
+      <domain>PRIMARY_HOSTNAME</domain>
+
+      <displayName>PRIMARY_HOSTNAME (Mail-in-a-Box)</displayName>
+      <displayShortName>PRIMARY_HOSTNAME</displayShortName>
+
+      <incomingServer type="imap">
+         <hostname>PRIMARY_HOSTNAME</hostname>
+         <port>993</port>
+         <socketType>SSL</socketType>
+         <username>%EMAILADDRESS%</username>
+         <authentication>password-cleartext</authentication>
+      </incomingServer>
+
+      <outgoingServer type="smtp">
+         <hostname>PRIMARY_HOSTNAME</hostname>
+         <port>587</port>
+         <socketType>STARTTLS</socketType>
+         <username>%EMAILADDRESS%</username>
+         <authentication>password-cleartext</authentication>
+         <addThisServer>true</addThisServer>
+         <useGlobalPreferredServer>true</useGlobalPreferredServer>
+      </outgoingServer>
+
+      <documentation url="https://PRIMARY_HOSTNAME/">
+         <descr lang="en">PRIMARY_HOSTNAME website.</descr>
+      </documentation>
+    </emailProvider>
+
+    <webMail>
+      <loginPage url="https://PRIMARY_HOSTNAME/mail/" />
+      <loginPageInfo url="https://PRIMARY_HOSTNAME/mail/" >
+        <username>%EMAILADDRESS%</username>
+        <usernameField id="rcmloginuser" name="_user" />
+        <passwordField id="rcmloginpwd" name="_pass" />
+        <loginButton id="rcmloginsubmit" />
+      </loginPageInfo>
+    </webMail>
+
+    <clientConfigUpdate url="https://PRIMARY_HOSTNAME/.well-known/autoconfig/mail/config-v1.1.xml" />
+
+</clientConfig>

conf/nginx.conf

@@ -38,6 +38,9 @@ server {
 	location = /mailinabox.mobileconfig {
 		alias /var/lib/mailinabox/mobileconfig.xml;
 	}
+	location = /.well-known/autoconfig/mail/config-v1.1.xml {
+		alias /var/lib/mailinabox/mozilla-autoconfig.xml;
+	}
 
 	# Roundcube Webmail configuration.
 	rewrite ^/mail$ /mail/ redirect;

setup/web.sh

@@ -53,6 +53,16 @@ cat conf/ios-profile.xml \
 	 > /var/lib/mailinabox/mobileconfig.xml
 chmod a+r /var/lib/mailinabox/mobileconfig.xml
 
+# Create the Mozilla Auto-configuration file which is exposed via the
+# nginx configuration at /.well-known/autoconfig/mail/config-v1.1.xml.
+# The format of the file is documented at:
+# https://wiki.mozilla.org/Thunderbird:Autoconfiguration:ConfigFileFormat
+# and https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Autoconfiguration/FileFormat/HowTo.
+cat conf/mozilla-autoconfig.xml \
+	| sed "s/PRIMARY_HOSTNAME/$PRIMARY_HOSTNAME/" \
+	 > /var/lib/mailinabox/mozilla-autoconfig.xml
+chmod a+r /var/lib/mailinabox/mozilla-autoconfig.xml
+
 # make a default homepage
 if [ -d $STORAGE_ROOT/www/static ]; then mv $STORAGE_ROOT/www/static $STORAGE_ROOT/www/default; fi # migration #NODOC
 mkdir -p $STORAGE_ROOT/www/default