diff --git a/conservancy/contacts/views.py b/conservancy/contacts/views.py
index daaf4d6712a48cb14fa8fcc66e9e927fe13c5864..ed5281202d96d95825b38e12f8c7c0bfb090a416 100644
--- a/conservancy/contacts/views.py
+++ b/conservancy/contacts/views.py
@@ -11,17 +11,27 @@ logger = logging.getLogger(__name__)
 class UnsubscribeForm(ModelForm):
     class Meta:
         model = Unsubscription
-        fields = ['email']
+        fields = ['email', 'mailout']
 
 
-# Exempt from CSRF protection so that it can be triggered by Gmail's on-click
-# unsubscribe.
-@csrf_exempt
+@csrf_exempt  # Submitted directly by Gmail and similar - no CSRF token.
 def unsubscribe(request):
+    """Endpoint for use with Gmail one-click unsubscribe or similar.
+
+    Gmail now requires "List-Unsubscribe" headers for senders over a certain
+    monthly volume (currently 5000 emails). Add the following headers to your
+    mailout:
+
+        List-Unsubscribe: <https://sfconservancy.org/contacts/unsubscribe/?email=foo@bar.com&mailout=jan2024-news>
+        List-Unsubscribe-Post: List-Unsubscribe=One-Click
+
+    Interfaces like Gmail will then provide a user interface to unsubscribe
+    which will hit this endpoint.
+    """
     if request.method == 'POST':
         logger.debug('Unsubscribe GET: %s', request.GET)
         logger.debug('Unsubscribe POST: %s', request.POST)
-        form = UnsubscribeForm(request.GET | request.POST)
+        form = UnsubscribeForm(request.GET)
         if form.is_valid():
             form.save()
             logger.info('Unsubscribed %s', form.cleaned_data['email'])