diff --git a/kube/boost/values-cppal-dev-gke.yaml b/kube/boost/values-cppal-dev-gke.yaml
index 8250ed28..984ca88d 100644
--- a/kube/boost/values-cppal-dev-gke.yaml
+++ b/kube/boost/values-cppal-dev-gke.yaml
@@ -120,6 +120,11 @@ Env:
       secretKeyRef:
         name: static-content
         key: bucket_name
+  - name: MAILGUN_API_KEY
+    valueFrom:
+      secretKeyRef:
+        name: mailgun
+        key: key
   # Static content cache timeout
   - name: STATIC_CACHE_TIMEOUT
     value: "60"
diff --git a/kube/boost/values-production-gke.yaml b/kube/boost/values-production-gke.yaml
index 73aae669..a1421b95 100644
--- a/kube/boost/values-production-gke.yaml
+++ b/kube/boost/values-production-gke.yaml
@@ -120,6 +120,11 @@ Env:
       secretKeyRef:
         name: static-content
         key: bucket_name
+  - name: MAILGUN_API_KEY
+    valueFrom:
+      secretKeyRef:
+        name: mailgun
+        key: key
   # Static content cache timeout
   - name: STATIC_CACHE_TIMEOUT
     value: "60"
diff --git a/kube/boost/values-stage-gke.yaml b/kube/boost/values-stage-gke.yaml
index e77260e2..20710eb4 100644
--- a/kube/boost/values-stage-gke.yaml
+++ b/kube/boost/values-stage-gke.yaml
@@ -120,6 +120,11 @@ Env:
       secretKeyRef:
         name: static-content
         key: bucket_name
+  - name: MAILGUN_API_KEY
+    valueFrom:
+      secretKeyRef:
+        name: mailgun
+        key: key
   # Static content cache timeout
   - name: STATIC_CACHE_TIMEOUT
     value: "60"