1 files changed, 15 insertions, 4 deletions
diff --git a/alot/mail/envelope.py b/alot/mail/envelope.py
index 655b5fe6..7f07eba4 100644
--- a/alot/mail/envelope.py
+++ b/alot/mail/envelope.py
@@ -59,10 +59,21 @@ class _EnvelopeHeaders:
         return self._vals[idx][0]
 
     def __delitem__(self, key):
-        idx = self._key_to_idx(key)
-        del self._keys_lower[idx]
-        del self._keys[idx]
-        del self._vals[idx]
+        deleted = False
+
+        while True:
+            try:
+                idx = self._key_to_idx(key)
+            except KeyError:
+                if deleted:
+                    return
+                raise
+
+            del self._keys_lower[idx]
+            del self._keys[idx]
+            del self._vals[idx]
+
+            deleted = True
 
     def __contains__(self, key):
         return key.lower() in self._keys_lower