Update README.md

Author: mkitchingh

README.md

@@ -2,6 +2,7 @@
 Microsoft removed the built in SMTP relay server from Windows. This is a replacement.
 Every other option I could find was no longer developed, overkill, or lacking features unless you used the paid version. 
 It is actively being developed and I will always try to keep it up to to date with current technologies.
+Everything is local. No telemetry, no update checks, no external connections of any kind beyond relaying your mail.
 Config GUI shown below. All options are pretty basic and self explanatory. Service will continue to run when the GUI is closed. It only listens on port 25.
 GUI will launch after install. It may take a few seconds while Windows scans it for the first time. Start menu shortcut is named SMTP Relay Config.