diff --git a/root/usr/share/mozilla-mcd/thunderbird.php b/root/usr/share/mozilla-mcd/thunderbird.php
index 193bc84..0f4e010 100644
--- a/root/usr/share/mozilla-mcd/thunderbird.php
+++ b/root/usr/share/mozilla-mcd/thunderbird.php
@@ -123,6 +123,10 @@ defaultPref("mail.content_disposition_type ", 1);
 defaultPref("mail.imap.expunge_option", 3);
 defaultPref("mail.imap.expunge_threshold_number", 100);
 
+// Adds the domain from your email address to the
+// recipients email address if it doesn't have a domain
+<?php echo TB_PREF;?>("mail.enable_autocomplete", true);
+
 // Hide useless messages
 <?php echo TB_PREF;?>("mail.ui.show.migration.on.upgrade", false);
 <?php echo TB_PREF;?>("app.update.showInstalledUI", false);