diff --git a/README.md b/README.md
index ef9302f..aa90d8e 100644
--- a/README.md
+++ b/README.md
@@ -6,15 +6,29 @@ Usage
 Begin listening for incoming SMTP messages, parse them, and post them to the
 specified HTTP endpoint.
 ```sh
-smtp2http https://dev-services.zingle.me/inbound-communication/email
+smtp2http https://example.com/foo
 ```
 
+### TLS Support
 Enable TLS using separate certificate and key files with signing CA cert.
 ```sh
-CERT=/etc/private/ssl/zingle.crt
-KEY=/etc/private/ssl/zingle.key
-CA=/etc/private/ssl/zingle-ca.crt
-smtp2http -T$CERT:$KEY:$CA https://dev-services.zingle.me/foo
+CERT=/etc/private/ssl/example.com.crt
+KEY=/etc/private/ssl/example.com.key
+CA=/etc/private/ssl/example.com-ca.crt
+smtp2http -T$CERT:$KEY:$CA https://example.com/foo
+```
+
+Enable TLS using cert and key files only.
+```sh
+CERT=/etc/private/ssl/example.com.crt
+KEY=/etc/private/ssh/example.com.key
+smtp2http -T$CERT:$KEY https://example.com/foo
+```
+
+Enable TLS using single PFX combined cert file.
+```sh
+CERT=/etc/private/ssl/example.com.pfx
+smtp2http -T$CERT https://example.com/foo
 ```
 
 Install
@@ -24,3 +38,23 @@ git clone git@github.com:Zingle/smtp2http.git
 cd smtp2http
 npm install -g
 ```
+
+Development
+-----------
+The SMTP protocol does not provide any way to set thc TCP port used for
+communication.  Because of this, development can be difficult if trying to
+use public mail providers because you must have an internet facing server
+listening on port 25.
+
+You can run something like the following to set up a reverse tunnel using
+a public server to which you have SSH access.
+
+```sh
+ssh -fNR 25:localhost:2025 root@example.com
+SMTP_PORT=2025 smtp2http
+```
+
+In this example, `example.com` is the public server to which you have access,
+`root` is a user with access to open low-numbered ports on that host, `25` is
+the port this host will listen on (standard SMTP port), and `2025` is the port
+`smtp2http` will listen on.
diff --git a/smtp2http.js b/smtp2http.js
index 77c1d32..fa108b6 100644
--- a/smtp2http.js
+++ b/smtp2http.js
@@ -87,5 +87,5 @@ smtp.createServer(serverOpts, function(req) {
 
         ack.accept();
     });
-}).listen(process.env.NODE_PORT || 25);
+}).listen(process.env.SMTP_PORT || 25);