The smtp server together with the /setup_smtp page was removed in checkin db5c2d399c143a04, so the link in the admin setup page should be removed as well.

Index: src/setup.c
==================================================================
--- src/setup.c
+++ src/setup.c
@@ -134,12 +134,10 @@
   setup_menu_entry("URL Aliases", "waliassetup",
     "Configure URL aliases");
   if( setup_user ){
     setup_menu_entry("Notification", "setup_notification",
       "Automatic notifications of changes via outbound email");
-    setup_menu_entry("Email-Server", "setup_smtp",
-      "Activate and configure the built-in email server");
     setup_menu_entry("Transfers", "xfersetup",
       "Configure the transfer system for this repository");
   }
   setup_menu_entry("Skins", "setup_skin",
     "Select and/or modify the web interface \"skins\"");