diff --git a/charts/mailproxy/v0.1.0/templates/mailauth-deployment.yaml b/charts/mailproxy/v0.1.0/templates/mailauth-deployment.yaml
index de79fcb..40f8448 100644
--- a/charts/mailproxy/v0.1.0/templates/mailauth-deployment.yaml
+++ b/charts/mailproxy/v0.1.0/templates/mailauth-deployment.yaml
@@ -36,6 +36,11 @@ spec:
               containerPort: {{ $port.number }}
               protocol: {{ $port.protocol }}
           {{- end }}
+          {{- if .Values.mailauth.relayHost }}
+          env:
+            - name: RELAY_HOST
+              value: {{ .Values.mailauth.relayHost | quote }}
+          {{- end }}
           livenessProbe:
             tcpSocket:
               port: {{ (index .Values.mailauth.service.ports 0).number }}
diff --git a/charts/mailproxy/v0.1.0/values.yaml b/charts/mailproxy/v0.1.0/values.yaml
index e0ade71..f7c79e4 100644
--- a/charts/mailproxy/v0.1.0/values.yaml
+++ b/charts/mailproxy/v0.1.0/values.yaml
@@ -44,6 +44,7 @@ mailauth:
       - name: php-fpm
         number: 9000
         protocol: TCP
+  relayHost: ""
   resources: {}
   # limits:
   #   cpu: 100m