diff --git a/4.1-Extensions.md b/4.1-Extensions.md
index 218e843..b28823a 100644
--- a/4.1-Extensions.md
+++ b/4.1-Extensions.md
@@ -1,11 +1,10 @@
-| **Extension**                                                                | **Source**                                                           | **Main Purpose**                                                                                                                                                                                                                                                                                                                                                                                                                                          |
-|------------------------------------------------------------------------------|----------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| [Cardbook](https://addons.thunderbird.net/addon/cardbook/)                   | [Source](https://gitlab.com/CardBook/CardBook)                       | Access [radicale](https://radicale.org) instance for contacts                                                                                                                                                                                                                                                                                                                                                                                             |
-| [Header Tools Lite](https://addons.thunderbird.net/addon/header-tools-lite/) | [Home](https://freeshell.de/~kaosmos/headertoolslite-en.html)        | Used to edit [`References`](https://en.wikipedia.org/wiki/Email#Header_fields) to have correct [`Message-ID`](https://en.wikipedia.org/wiki/Message-ID) to maintain [threading on mailing lists when not subscribed](https://superuser.com/questions/1177870/how-to-manually-set-the-in-reply-to-header-in-thunderbird/1189889). Unmaintained and incompatible with Thunderbird 68.0+, however there is an [alternative solution](#alternative-solution). |
-| [Lightning](http://www.mozilla.org/projects/calendar/)                       | [Source](https://hg.mozilla.org/comm-central/file/tip/calendar)      | Calendars                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
-| [Markdown Here](https://markdown-here.com)                                   | [Source](https://github.com/adam-p/markdown-here)                    | Write pretty HTML emails sometimes                                                                                                                                                                                                                                                                                                                                                                                                                        |
-| [Enigmail](https://addons.thunderbird.net/addon/enigmail/)                   | [Source](https://www.enigmail.net/index.php/en/download/source-code) | PGP                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
-
+| **Extension**                                                                | **Source**                                                           | **Main Purpose**                                                                                                                                                                                                                                                                                                                                                                                                                                          | **Recommended before Thunderbird...**                                                                         |
+|------------------------------------------------------------------------------|----------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:-------------------------------------------------------------------------------------------------------------:|
+| [Cardbook](https://addons.thunderbird.net/addon/cardbook/)                   | [Source](https://gitlab.com/CardBook/CardBook)                       | Access [radicale](https://radicale.org) instance for contacts                                                                                                                                                                                                                                                                                                                                                                                             | [102](https://blog.thunderbird.net/2022/06/thunderbird-102-released-a-serious-upgrade-to-your-communication/) |
+| [Header Tools Lite](https://addons.thunderbird.net/addon/header-tools-lite/) | [Home](https://freeshell.de/~kaosmos/headertoolslite-en.html)        | Used to edit [`References`](https://en.wikipedia.org/wiki/Email#Header_fields) to have correct [`Message-ID`](https://en.wikipedia.org/wiki/Message-ID) to maintain [threading on mailing lists when not subscribed](https://superuser.com/questions/1177870/how-to-manually-set-the-in-reply-to-header-in-thunderbird/1189889). Unmaintained and incompatible with Thunderbird 68.0+, however there is an [alternative solution](#alternative-solution). |                                                                                                               |
+| [Lightning](http://www.mozilla.org/projects/calendar/)                       | [Source](https://hg.mozilla.org/comm-central/file/tip/calendar)      | Calendars                                                                                                                                                                                                                                                                                                                                                                                                                                                 | [38](https://support.mozilla.org/en-US/kb/calendar-integration-thunderbird)                                   |
+| [Markdown Here](https://markdown-here.com)                                   | [Source](https://github.com/adam-p/markdown-here)                    | Write pretty HTML emails sometimes                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                               |
+| [Enigmail](https://addons.thunderbird.net/addon/enigmail/)                   | [Source](https://www.enigmail.net/index.php/en/download/source-code) | PGP                                                                                                                                                                                                                                                                                                                                                                                                                                                       | [78](https://support.mozilla.org/en-US/kb/openpgp-thunderbird-howto-and-faq)                                  |
 
 ### Alternative solution