Many times I've seen similar topics, but most of these were about zimlet's access to external web-resources. But what about the ZCS itself?

I had set up proper zimbraHttpProxyURL:

Code:
$ zmprov gacf|grep roxyURL
zimbraHttpProxyURL: http://172.21.122.225:8080/
Code:
$ zmprov gs my-server-name|grep roxyURL
zimbraHttpProxyURL: http://172.21.122.225
HTTPProxyPort 8080
Second (per server) setting was not set directly for server, it is inherited from global settings.

Proxy accepting requests from server's host. Proof: freshclam updates succesfully after
Code:
$ grep -i proxy conf/freshclam.conf.in
# Proxy settings
HTTPProxyServer 172.21.122.225
HTTPProxyPort 8080
But in mailbox.log I can see only:

Code:
2012-09-26 13:50:53,389 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] soap - BatchRequest
2012-09-26 13:51:56,534 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out
2012-09-26 13:51:56,535 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - Retrying request
2012-09-26 13:52:59,638 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out
2012-09-26 13:52:59,638 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - Retrying request
2012-09-26 13:54:02,742 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out
2012-09-26 13:54:02,742 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] HttpMethodDirector - Retrying request
2012-09-26 13:55:05,853 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] SoapEngine - handler exception
com.zimbra.common.service.ServiceException: system failure: Failed to send HTTP request to version check script.
ExceptionId:qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest:1348628105846:bbbe29649432b7fd
Code:service.FAILURE
	at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:258)
	at com.zimbra.cs.service.versioncheck.VersionCheck.checkVersion(VersionCheck.java:293)
	at com.zimbra.cs.service.versioncheck.VersionCheck.handle(VersionCheck.java:70)
	at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEngine.java:421)
	at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:266)
	at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:157)
	at com.zimbra.soap.SoapServlet.doWork(SoapServlet.java:290)
	at com.zimbra.soap.SoapServlet.doPost(SoapServlet.java:206)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at com.zimbra.cs.servlet.ZimbraServlet.service(ZimbraServlet.java:208)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:565)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1361)
	at com.zimbra.cs.servlet.SetHeaderFilter.doFilter(SetHeaderFilter.java:57)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
	at org.eclipse.jetty.servlets.UserAgentFilter.doFilter(UserAgentFilter.java:77)
	at org.eclipse.jetty.servlets.GzipFilter.doFilter(GzipFilter.java:181)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
	at org.eclipse.jetty.servlets.DoSFilter.doFilterChain(DoSFilter.java:464)
	at org.eclipse.jetty.servlets.DoSFilter.doFilter(DoSFilter.java:327)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:477)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
	at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250)
	at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
	at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:312)
	at org.eclipse.jetty.server.handler.DebugHandler.handle(DebugHandler.java:77)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
	at org.eclipse.jetty.server.Server.handle(Server.java:349)
	at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:452)
	at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:894)
	at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:948)
	at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:857)
	at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
	at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:77)
	at org.eclipse.jetty.io.nio.SslConnection.handle(SslConnection.java:191)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:606)
	at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:46)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
	at java.lang.Thread.run(Thread.java:722)
Caused by: java.net.ConnectException: Connection timed out
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
	at java.net.Socket.connect(Socket.java:579)
	at java.net.Socket.connect(Socket.java:528)
	at java.net.Socket.<init>(Socket.java:425)
	at java.net.Socket.<init>(Socket.java:280)
	at javax.net.DefaultSocketFactory.createSocket(SocketFactory.java:284)
	at com.zimbra.common.net.ProtocolSocketFactoryWrapper.createSocket(ProtocolSocketFactoryWrapper.java:49)
	at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
	at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
	at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
	at com.zimbra.cs.service.versioncheck.VersionCheck.checkVersion(VersionCheck.java:270)
	... 47 more
2012-09-26 13:55:05,855 INFO  [qtp46126256-2898:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] soap - (batch) VersionCheckRequest elapsed=252465
2012-09-26 13:55:05,887 INFO  [qtp46126256-2903:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] soap - BatchRequest
2012-09-26 13:55:05,889 INFO  [qtp46126256-2903:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] soap - (batch) GetAllConfigRequest elapsed=2
2012-09-26 13:55:05,890 INFO  [qtp46126256-2903:https://172.21.127.133:7071/service/admin/soap/BatchRequest] [name=admin@mydomain.ru;mid=2;ip=172.21.122.134;ua=ZimbraWebClient - FF15 (Win);] soap - (batch) VersionCheckRequest elapsed=0
and proxy's logs does not contain any traces of ZCS's attemtps to reach outside.

What can be wrong? Or zimbraHttpProxyURL is intended for zimlets only? But ~/zimlets-deployed/com_zimbra_adminversioncheck/com_zimbra_adminversioncheck.js is the zimlet, isn't it? Then why it does not attempt to use zimbraHttpProxyURL for requests?

Thank you!