Unitl using zimbra 5 external pop work fine.
After upgrading it stop working. If I set a cleartext conection Zimbra always try a ssl connection.

How a can solve?

Log....

2009-06-22 13:16:43,666 INFO [btpool0-8] [name=xxxx@xxxxxxxxxxxxxx;mid=13;ip=192.168.1.140;u a=ZimbraWebClient - FF3.0 (Win)/6.0.0_BETA2_1547.RHEL5;] soap - TestDataSourceRequest
2009-06-22 13:16:43,666 INFO [btpool0-8] [name=xxxx@xxxxxxxxxxxxxx;mid=13;ip=192.168.1.140;u a=ZimbraWebClient - FF3.0 (Win)/6.0.0_BETA2_1547.RHEL5;] datasource - Testing: DataSource: { id=TestId, type=pop3, isEnabled=false, name=Test, host=xxxxxxxxxxxxxx, port=110, connectionType=cleartext, username=xxxx@xxxxxxxxxxxxxx, folderId=-1 }
2009-06-22 13:16:43,981 WARN [btpool0-8] [name=xxxx@xxxxxxxxxxxxxx;mid=13;ip=192.168.1.140;u a=ZimbraWebClient - FF3.0 (Win)/6.0.0_BETA2_1547.RHEL5;] datasource - Test failed: DataSource: { id=TestId, type=pop3, isEnabled=false, name=Test, host=xxxxxxxxxxxxxx, port=110, connectionType=cleartext, username=xxxx@xxxxxxxxxxxxxx, folderId=-1 }
com.zimbra.common.service.ServiceException: system failure: Unable to connect to POP3 server: DataSource: { id=TestId, type=pop3, isEnabled=false, name=Test, host=xxxxxxxxxxxxxx, port=110, connectionType=cleartext, username=xxx@xxxxxxxxxxxxxx, folderId=-1 }
ExceptionId:btpool0-8:1245669403980:0e499bf9cf19fd99
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:251)
at com.zimbra.cs.datasource.Pop3Sync.connect(Pop3Sync .java:138)
at com.zimbra.cs.datasource.Pop3Sync.test(Pop3Sync.ja va:83)
at com.zimbra.cs.datasource.DataSourceManager.test(Da taSourceManager.java:52)
at com.zimbra.cs.service.mail.TestDataSource.handle(T estDataSource.java:125)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:415)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:272)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:156)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:273)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:187)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1148)
at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81)
at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:129)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1139)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:378)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:417)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152)
at org.mortbay.jetty.handler.rewrite.RewriteHandler.h andle(RewriteHandler.java:230)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:534)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:879)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:747)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:409)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:451)
Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
at com.sun.net.ssl.internal.ssl.InputRecord.handleUnk nownRecord(InputRecord.java:523)
at com.sun.net.ssl.internal.ssl.InputRecord.read(Inpu tRecord.java:355)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRec ord(SSLSocketImpl.java:782)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.perform InitialHandshake(SSLSocketImpl.java:1089)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHa ndshake(SSLSocketImpl.java:1116)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHa ndshake(SSLSocketImpl.java:1100)
at com.zimbra.common.util.CustomSSLSocket.startHandsh ake(CustomSSLSocket.java:213)
at com.zimbra.cs.mailclient.MailConnection.startTls(M ailConnection.java:292)
at com.zimbra.cs.mailclient.MailConnection.connect(Ma ilConnection.java:88)
at com.zimbra.cs.datasource.Pop3Sync.connect(Pop3Sync .java:130)
... 33 more