--- comm/mail/components/shell/nsMailGNOMEIntegration.cpp.orig	2018-09-19 15:07:33.630000000 +0200
+++ comm/mail/components/shell/nsMailGNOMEIntegration.cpp	2018-09-19 15:08:31.450000000 +0200
@@ -98,6 +98,12 @@
   NS_ENSURE_SUCCESS(rv, rv);
 
   rv = appPath->GetNativePath(mAppPath);
+
+   /* This path of thunderbird is hardcoded for the default path setting
+   * And the above code is not used.
+   */
+  mAppPath.Assign ("/usr/bin/thunderbird");
+
   return rv;
 }