diff --git a/_unittests/ut_automation_students/test_pitch_automatique.py b/_unittests/ut_automation_students/test_pitch_automatique.py
index 4cbeca852..7e823fd18 100644
--- a/_unittests/ut_automation_students/test_pitch_automatique.py
+++ b/_unittests/ut_automation_students/test_pitch_automatique.py
@@ -113,7 +113,7 @@ def test_enumerate_feedback(self):
         xls = os.path.join(data, "groupes_eleves_pitch.xlsx")
         df = pandas.read_excel(xls, sheetname=0, index=False)
         comment = pandas.read_excel(xls, sheetname=1, header=None, index=False)
-        mails = list(enumerate_feedback(df, comment))
+        mails = list(enumerate_feedback(df, comment, exc=False, fLOG=fLOG))
         for i, m in enumerate(mails):
             fLOG("------------", i)
             name = os.path.join(temp, "m%d.html" % i)
diff --git a/src/ensae_teaching_cs/automation_students/send_feedback.py b/src/ensae_teaching_cs/automation_students/send_feedback.py
index 74f6837af..e14573acc 100644
--- a/src/ensae_teaching_cs/automation_students/send_feedback.py
+++ b/src/ensae_teaching_cs/automation_students/send_feedback.py
@@ -29,7 +29,7 @@ def enumerate_feedback(df1, df2, col_group="Groupe", col_subject="Sujet",
                        col_name="Name", subject="Projet informatique, feedback sur le pitch",
                        begin="Bonjour,\n\nVoici mon feedback sur votre pitch. Ce mail est automatisé. Veuillez vérifier les informations.\n\n",
                        end="Xavier", text_comments="Remarques générales", cc=None,
-                       template=template_mail_feedback, engine="jinja2", fLOG=noLOG):
+                       template=template_mail_feedback, engine="jinja2", exc=True, fLOG=noLOG):
     """
     sends feedback to students
 
@@ -47,6 +47,7 @@ def enumerate_feedback(df1, df2, col_group="Groupe", col_subject="Sujet",
     @param      template        template of the mail
     @param      text_comments   sentance before the general comments
     @param      engine          engine for the template
+    @param      exc             raise an exception if there is no mail
     @return                     list of mails
 
     Example of dataframe containing feedback:
@@ -108,4 +109,9 @@ def sums2(spl):
                 k = k[4:]
             context[k] = v
         text = apply_template(template, context, engine=engine)
+        if mail is None or "@" not in mail:
+            if exc:
+                raise ValueError("No mail for:\n" + text)
+            else:
+                fLOG("No mail for:\n" + text)
         yield (mail, text)