diff --git a/colloscope/icalexport.py b/colloscope/icalexport.py
index 355b116..a2ad358 100644
--- a/colloscope/icalexport.py
+++ b/colloscope/icalexport.py
@@ -5,6 +5,16 @@ from icalendar import Calendar, Event, vCalAddress, vText
 
 from colloscope.models import *
 
+def emailize(nom, prenom=None):
+    if prenom is not None:
+        return "{}.{}@example.com" \
+                .format(
+                        prenom.replace(" ", "_").lower(),
+                        nom.replace(" ", "_").lower()
+                        )
+    else:
+        return "{}@example.com" \
+                .format(nom.replace(" ", "_").lower())
 
 def to_calendar(etudiant, periode):
     cal = Calendar()
@@ -33,13 +43,13 @@ def to_calendar(etudiant, periode):
         event.add("location", f"{rotation.creneau.salle} ({rotation.creneau.periode.classe.lycee})")
         event.add("matiere", str(rotation.creneau.matiere))
 
-        organizer = vCalAddress("mailto:unknown@mp2i-vms.fr")
+        organizer = vCalAddress(f"mailto:{emailize(rotation.creneau.colleur.nom)}")
         organizer.params["cn"] = vText(str(rotation.creneau.colleur))
         organizer.params["role"] = vText("Colleur")
         event.add("organizer", organizer)
 
         for e in rotation.groupe_effectif():
-            attendee = vCalAddress("mailto:unknown@mp2i-vms.fr")
+            attendee = vCalAddress("mailto:{emailize(e.nom, prenom=e.prenom)}")
             attendee.params["cn"] = vText(str(e))
             attendee.params["role"] = vText("Etudiant")