The server URL configured in the Administration UI (on Administration | Global Settings page) is used by the server to generate links to the server when the URL cannot be derived from any other parameter. These cases include Notifications (email, Jabber, etc.) and some other actions performed not within a web request. All generated links will be prefixed by this URL.
Please make sure the server is accessible by the URL specified.
In most cases TeamCity correctly autodetects its own URL and sets it as the Server URL. However, sometimes autodetection is not possible/correct (for example, when the TeamCity server is running behind the Apache proxy). For such cases you can specify the server URL on the Administration | Global Settings page, or in the
<TeamCity data directory>/config/main-config.xml file using the following format (no server restart is required after the change):