Index: gc_lang/fr/build.py
==================================================================
--- gc_lang/fr/build.py
+++ gc_lang/fr/build.py
@@ -10,10 +10,11 @@
 
 def build (sLang, dVars, spLangPack):
     "complementary build launched from make.py"
     createWebExtension(sLang, dVars)
     createThunderbirdExtension(sLang, dVars, spLangPack)
+    createMailExtension(sLang, dVars, spLangPack)
     createNodeJSPackage(sLang)
 
 
 def createWebExtension (sLang, dVars):
     "create Web-extension"
@@ -37,28 +38,39 @@
             for sOpt in lLineOpt:
                 sHTML += f'  <p><input type="checkbox" id="option_{sOpt}" class="gc_option" data-option="{sOpt}"/><label id="option_label_{sOpt}" for="option_{sOpt}" data-l10n-id="option_{sOpt}">{dVars["dOptLabel"][sLang][sOpt][0]}</label></p>\n'
         sHTML += '</div>\n'
     return sHTML
 
+
+def createMailExtension (sLang, dVars, spLangPack):
+    "create extension for Thunderbird (as MailExtension)"
+    print("Building extension for Thunderbird (MailExtension)")
+    spfZip = "_build/" + dVars['tb_identifier'] + "-v" + dVars['version'] + '.mailext.xpi'
+    hZip = zipfile.ZipFile(spfZip, mode='w', compression=zipfile.ZIP_DEFLATED)
+    _copyGrammalecteJSPackageInZipFile(hZip, spLangPack)
+    for spf in ["LICENSE.txt", "LICENSE.fr.txt"]:
+        hZip.write(spf)
+    dVars = _createOptionsForThunderbird(dVars)
+    helpers.addFolderToZipAndFileFile(hZip, "gc_lang/"+sLang+"/mailext", "", dVars, True)
+    hZip.close()
+    spBetaExtension = dVars['win_tb_beta_extension_filepath']  if platform.system() == "Windows"  else dVars['linux_tb_beta_extension_filepath']
+    file_util.copy_file(spfZip, spBetaExtension + "/" + dVars['tb_identifier']+ ".xpi")  # Filename for TB is just <identifier.xpi>
+
 
 def createThunderbirdExtension (sLang, dVars, spLangPack):
-    "create extension for Thunderbird"
+    "create extension for Thunderbird (as XUL addon)"
     print("Building extension for Thunderbird")
-    sExtensionName = dVars['tb_identifier'] + "-v" + dVars['version'] + '.xpi'
-    spfZip = "_build/" + sExtensionName
+    spfZip = "_build/" + dVars['tb_identifier'] + "-v" + dVars['version'] + '.xpi'
     hZip = zipfile.ZipFile(spfZip, mode='w', compression=zipfile.ZIP_DEFLATED)
     _copyGrammalecteJSPackageInZipFile(hZip, spLangPack)
     for spf in ["LICENSE.txt", "LICENSE.fr.txt"]:
         hZip.write(spf)
     dVars = _createOptionsForThunderbird(dVars)
     helpers.addFolderToZipAndFileFile(hZip, "gc_lang/"+sLang+"/tb", "", dVars, True)
     hZip.close()
     spDebugProfile = dVars['win_tb_debug_extension_path']  if platform.system() == "Windows"  else dVars['linux_tb_debug_extension_path']
     helpers.unzip(spfZip, spDebugProfile)
-    spfBetaExtension = dVars['win_tb_beta_extension_filepath']  if platform.system() == "Windows"  else dVars['linux_tb_beta_extension_filepath']
-    #helpers.unzip(spfZip, spBetaProfile)
-    file_util.copy_file(spfZip, spfBetaExtension)
 
 
 def _createOptionsForThunderbird (dVars):
     dVars['sXULTabs'] = ""
     dVars['sXULTabPanels'] = ""

Index: gc_lang/fr/config.ini
==================================================================
--- gc_lang/fr/config.ini
+++ gc_lang/fr/config.ini
@@ -8,11 +8,11 @@
 # always use 3 numbers for version: x.y.z
 version = 1.1.1
 author = Olivier R.
 provider = Grammalecte.net
 link = https://grammalecte.net
-description = Correcteur grammatical pour le français.
+description = Correcteur grammatical, orthographique et typographique pour le français.
 extras = README_fr.txt
 logo = logo.png
 
 # main dictionary
 lexicon_src = lexicons/French.lex
@@ -59,12 +59,12 @@
 win_tb_beta_path = C:\Program Files\Thunderbird Daily\thunderbird.exe
 linux_tb_path = /usr/bin/thunderbird
 linux_tb_beta_path = /usr/bin/thunderbird
 win_tb_debug_extension_path = D:\_temp\tb-debug.profile\extensions\French-GC-TB@grammalecte.net
 linux_tb_debug_extension_path = ~/tb-debug.profile/extensions/French-GC-TB@grammalecte.net
-win_tb_beta_extension_filepath = D:\_temp\tb-beta.profile\extensions\French-GC-TB@grammalecte.net.xpi
-linux_tb_beta_extension_filepath = ~/tb-beta.profile/extensions/French-GC-TB@grammalecte.net.xpi
+win_tb_beta_extension_filepath = D:\_temp\tb-beta.profile\extensions
+linux_tb_beta_extension_filepath = ~/tb-beta.profile/extensions
 # Set Thunderbird folder in your PATH variable
 # Create a local profile:
 #     	thunderbird -CreateProfile "debug _build\tb-debug.profile"
 # Or you can use the GUI with:
 #	 	thunderbird -P

Index: helpers.py
==================================================================
--- helpers.py
+++ helpers.py
@@ -34,11 +34,11 @@
         if os.path.isdir(spInstall):
             eraseFolder(spInstall)
             with zipfile.ZipFile(spfZip) as hZip:
                 hZip.extractall(spDest)
         else:
-            print("# folder not found")
+            print("# folder <" + spDest + "> not found")
     else:
         print("path destination is empty")
 
 
 def eraseFolder (sp):
@@ -94,9 +94,9 @@
         spfDst = (spDst + "/" + sf).strip("/ ")
         if os.path.isdir(spfSrc):
             if bRecursive:
                 addFolderToZipAndFileFile(hZip, spfSrc, spfDst, dVars, bRecursive)
         else:
-            if spfSrc.endswith((".py", ".js", ".css", ".xcu", ".xul", ".rdf", ".dtd", ".properties")):
+            if spfSrc.endswith((".py", ".js", ".json", ".css", ".xcu", ".xul", ".rdf", ".dtd", ".properties")):
                 hZip.writestr(spfDst, fileFile(spfSrc, dVars))
             else:
                 hZip.write(spfSrc, spfDst)