diff --git a/etc/thunderbird/pref/40_security-misc.js b/etc/thunderbird/pref/40_security-misc.js
index 931f9d2..80afc04 100644
--- a/etc/thunderbird/pref/40_security-misc.js
+++ b/etc/thunderbird/pref/40_security-misc.js
@@ -10,6 +10,7 @@
 // https://forums.whonix.org/t/enable-network-idn-show-punycode-by-default-in-thunderbird-to-fix-url-not-showing-real-domain-name-homograph-attack-punycode/8415
 pref("network.IDN_show_punycode", true);
 
+//### Telemetry
 // Disable all and any kind of telemetry by default
 pref("toolkit.telemetry.enabled", false);
 pref("toolkit.telemetry.unified", false);
@@ -21,22 +22,50 @@ pref("toolkit.telemetry.firstShutdownPing.enabled", false);
 pref("toolkit.telemetry.newProfilePing.enabled", false);
 pref("toolkit.telemetry.server", ""); // Defense in depth
 pref("toolkit.telemetry.server_owner", ""); // Defense in depth
-pref("datareporting.healthreport.uploadEnabled", false);
-pref("datareporting.policy.dataSubmissionEnabled", false);
 pref("toolkit.telemetry.coverage.opt-out", true); // from Firefox
 pref("toolkit.coverage.opt-out", true); // from Firefox
 
+// Disable Thunderbird archiving telemetry data locally
+// Thunderbird saves data to ~/.thunderbird/profile.default/datareporting/ 
+pref("datareporting.healthreport.about.reportUrl", "data:text/plain,");
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.healthreport.service.enabled", false);
+pref("datareporting.healthreport.service.firstRun", false);
+pref("datareporting.healthreport.service.lastDataSubmissionRequested", 0);
+pref("datareporting.healthreport.service.lastDataSubmissionSuccessful", 0);
+pref("datareporting.healthreport.service.submitEnabled", false);
+
 // Disable implicit outbound traffic
 pref("network.connectivity-service.enabled", false);
 pref("network.prefetch-next", false);
 pref("network.dns.disablePrefetch", true);
 pref("network.predictor.enabled", false);
 
+//### Security
 // No need to explain the problems with javascript
 // If you want javascript, use your browser
 // Thunderbird needs no javascript
 // pref("javascript.enabled", false); // Will break setting up services that require redirecting to their javascripted webpage for login, like gmail etc. So commented out for now.
 
+// JavaScript hardening. Source https://gitlab.torproject.org/tpo/applications/tor-browser/-/blob/tor-browser-115.10.0esr-13.5-1/browser/components/securitylevel/content/securityLevel.js?ref_type=heads
+// (we are applying the "high" profile)
+pref("javascript.options.ion", false);
+pref("javascript.options.baselinejit", false);
+pref("javascript.options.native_regexp", false);
+pref("media.webaudio.enabled", false);
+pref("mathml.disabled", true);
+pref("gfx.font_rendering.opentype_svg.enabled",  false);
+pref("svg.disabled",  true);
+
+// Disable WebGL.
+pref("webgl.disabled", true);
+
+// Disable WebM, WAV, Ogg, PeerConnection.
+pref("media.navigator.enabled", false);
+pref("media.peerconnection.enabled", false);
+pref("media.cache_size", 0);
+
 // Disable scripting when viewing pdf files
 user_pref("pdfjs.enableScripting", false);
 
@@ -50,6 +79,7 @@ pref("network.cookie.cookieBehavior", 2);
 // But we want it gone for good for no information leak at all
 // https://hg.mozilla.org/comm-central/rev/cbbbc8d93cd7
 pref("mailnews.headers.sendUserAgent", false);
+pref("general.useragent.override", "");
 
 // Normally we send emails after marking them with a time stamp
 // That includes our local time zone
@@ -57,3 +87,56 @@ pref("mailnews.headers.sendUserAgent", false);
 // And rounds the time stamp to the closes minute
 // https://hg.mozilla.org/comm-central/rev/98aa0bf2e719
 pref("mail.sanitize_date_header", true);
+
+//### Performance
+// Compact folders on exit
+// Compact when it will save over 100 KB
+pref("mail.folder.compact_on_exit", true);
+pref("mail.folder.compact_threshold", 100);
+
+//### Privacy
+// Geolocation
+pref("geo.enabled", false);
+pref("geo.provider.use_geoclue", false)
+pref("geo.provider.network.url", "")
+
+// Disable Google Safe Browsing (#22567).
+pref("browser.safebrowsing.enabled", false);
+pref("browser.safebrowsing.malware.enabled", false);
+
+// Disable Microsoft Family Safety (From TBB: #21686).
+pref("security.family_safety.mode", 0);
+
+// Likely privacy violations
+// https://blog.torproject.org/blog/experimental-defense-website-traffic-fingerprinting
+// https://bugs.torproject.org/3914
+pref("network.http.pipelining", true);
+pref("network.http.pipelining.aggressive", true);
+pref("network.http.pipelining.maxrequests", 12);
+pref("network.http.connection-retry-timeout", 0);
+pref("network.http.max-persistent-connections-per-proxy", 256);
+pref("network.http.pipelining.reschedule-timeout", 15000);
+pref("network.http.pipelining.read-timeout", 60000);
+
+// We do not fully understand the privacy issues of the SPDY protocol
+pref("network.http.spdy.enabled", false);
+
+// Don't save email addresses from sent emails
+// Do not automatically add outgoing sent emails to address book "Collected Addresses" for privacy
+pref("mail.collect_email_address_outgoing", false);
+
+// Clean mailbox server-side
+// Delete messages from server regardless if POP3 or IMAP is set as protocol for accounts
+// Delete POP3 messages from server when moved for example when moved to trash in Thunderbird
+// Delete IMAP messages from server when deleted or marked for deletion in Thunderbird
+pref("mail.pop3.deleteFromServerOnMove", true);
+pref("mail.imap.expunge_after_delete", true);
+
+// Don't leak the locale "Date & Time" via reply quote header
+pref("mailnews.reply_header_type", 1);
+pref("mailnews.reply_header_authorwrotesingle", "#1 wrote:");
+
+//### Nuances & Annoyances 
+// Disable donation banner
+pref("mailnews.donationbanner.enabled", false);
+pref("app.donation.eoy.version.viewed", 999999);