diff --git a/src/docs/user/configuration/configuring_file_storage.diviner b/src/docs/user/configuration/configuring_file_storage.diviner
--- a/src/docs/user/configuration/configuring_file_storage.diviner
+++ b/src/docs/user/configuration/configuring_file_storage.diviner
@@ -164,6 +164,8 @@
 
   - `amazon-s3.access-key`: Your AWS access key.
   - `amazon-s3.secret-key`: Your AWS secret key.
+  - `amazon-s3.region`: Your AWS S3 region.
+  - `amazon-s3.endpoint`: Your AWS S3 endpoint.
   - `storage.s3.bucket`: S3 bucket name where files should be stored.
 
 Testing Storage Engines
diff --git a/src/docs/user/configuration/configuring_inbound_email.diviner b/src/docs/user/configuration/configuring_inbound_email.diviner
--- a/src/docs/user/configuration/configuring_inbound_email.diviner
+++ b/src/docs/user/configuration/configuring_inbound_email.diviner
@@ -128,6 +128,7 @@
   - Add a Mailgun route with a `catch_all()` rule which takes the action
     `forward("https://phabricator.example.com/mail/mailgun/")`. Replace the
     example domain with your actual domain.
+  - Set the `mailgun.api-key` config key to your Mailgun API key.
 
 = SendGrid Setup =