diff --git a/docs/operations.md b/docs/operations.md
index 7836be3..fb75a37 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -208,6 +208,13 @@ test checkout. The generated file uses the ordinary runtime names:
 | Verified Android links | `ANDROID_APP_LINKS_PACKAGE_NAME`, `ANDROID_APP_LINKS_SHA256_CERT_FINGERPRINTS` |
 | Transactional email | `SMTP_*`, sender, and `SUPPORT_INBOX_ADDRESS` |
 
+`SUPPORT_INBOX_ADDRESS` configures `Reply-To` and the optional operator-alert
+destination. The environment readiness script validates only that this value is
+present and syntactically usable; it does not prove that the domain has inbound
+MX routing or that the mailbox is monitored. Check DNS and perform an actual
+inbound delivery/reply test before presenting the address as a public support
+contact.
+
 Do not reuse a Google client, VAPID private key, Firebase project/service
 account, SMTP credential, or Android signing key between dev and production.
 The public Firebase Android values are build configuration; the Base64 FCM
diff --git a/docs/public-launch-checklist.md b/docs/public-launch-checklist.md
index d7317bb..a54d353 100644
--- a/docs/public-launch-checklist.md
+++ b/docs/public-launch-checklist.md
@@ -67,6 +67,9 @@ The release check covers the application origin and secrets, database
 selection, SMTP and support routing, Google OAuth, browser VAPID, Firebase/FCM,
 Android package/signing configuration, and production App Links. It does not
 prove that external providers will deliver successfully after deployment.
+In particular, a configured `SUPPORT_INBOX_ADDRESS` is not evidence of inbound
+mail delivery: verify its MX routing and complete a real receive-and-reply test
+before using it in Google Play or public support pages.
 
 ## 3. Record human and legal decisions
 
diff --git a/scripts/check-environment-readiness.sh b/scripts/check-environment-readiness.sh
index dca5713..8bfaa7c 100755
--- a/scripts/check-environment-readiness.sh
+++ b/scripts/check-environment-readiness.sh
@@ -226,9 +226,10 @@ else
 fi
 
 if is_set SUPPORT_INBOX_ADDRESS; then
-  ready "support inbox" "operator destination is configured"
+  ready "support reply address" \
+    "address is configured; inbound DNS and mailbox delivery require a separate test"
 else
-  missing "support inbox" "SUPPORT_INBOX_ADDRESS"
+  missing "support reply address" "SUPPORT_INBOX_ADDRESS"
 fi
 
 rate_limit_policies_json=$(value RATE_LIMIT_POLICIES_JSON)