Upgraded to 5.0 tonight and now I can't send or receive email using the web client. Here is the info from the mailbox.log that I was able to capture...

2008-01-11 01:58:33,963 INFO [btpool0-10] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] im - IMRosterNotification:
2008-01-11 01:58:35,852 INFO [IndexWritersSweeperThread] [] index - open index writers sweep: before=1, closed=0, after=1 (0ms)
2008-01-11 01:58:53,797 INFO [btpool0-0] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] SendMsg - <SendMsg> LC(mbox=a25cdbfd-dea6-4ee6-9652-4bbd64d6163f, sessions=191)
2008-01-11 01:58:53,799 INFO [btpool0-0] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] smtp - Sending message: Message-ID=<1143271849.621200034733799.JavaMail.root@mail0 2>, replyType=r
2008-01-11 01:58:53,831 INFO [btpool0-0] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] mailbox - Added message: id=75771, digest=9f,WHqvdOET+hK9k,Dnw6WX0EvM=, folderId=5, folderName=Sent
2008-01-11 01:59:05,858 INFO [IndexWritersSweeperThread] [] index - open index writers sweep: before=1, closed=0, after=1 (0ms)
2008-01-11 01:59:13,843 WARN [btpool0-0] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] smtp - exception occurred during SendMsg
com.zimbra.cs.mailbox.MailSender$SafeMessagingExce ption: Read timed out; chained exception is:
java.net.SocketTimeoutException: Read timed out
at com.sun.mail.smtp.SMTPTransport.readServerResponse (SMTPTransport.java:1598)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTra nsport.java:1356)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SM TPTransport.java:399)
at javax.mail.Service.connect(Service.java:275)
at javax.mail.Service.connect(Service.java:156)
at javax.mail.Service.connect(Service.java:105)
at javax.mail.Transport.send0(Transport.java:168)
at javax.mail.Transport.send(Transport.java:98)
at com.zimbra.cs.mailbox.MailSender.sendMessage(MailS ender.java:428)
at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:248)
at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:115)
at com.zimbra.cs.service.mail.SendMsg.doSendMessage(S endMsg.java:185)
at com.zimbra.cs.service.mail.SendMsg.handle(SendMsg. java:150)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:342)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:208)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:113)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:272)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:174)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1093)
at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81)
at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:132)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1084)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:360)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:716)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:406)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:211)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.handler.RewriteHandler.handle(Re writeHandler.java:176)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:313)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:506)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:205)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
2008-01-11 01:59:13,845 INFO [btpool0-0] [name=jamie@learningfocused.com;mid=3;ip=24.196.195 .122;ua=ZimbraWebClient - FF2.0 (Win)/5.0.1_GA_1902.RHEL4_64;] SoapEngine - handler exception
com.zimbra.common.service.ServiceException: system failure: MessagingException
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:183)
at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:315)
at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:115)
at com.zimbra.cs.service.mail.SendMsg.doSendMessage(S endMsg.java:185)
at com.zimbra.cs.service.mail.SendMsg.handle(SendMsg. java:150)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:342)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:208)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:113)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:272)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:174)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1093)
at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81)
at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:132)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1084)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:360)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:716)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:406)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:211)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.handler.RewriteHandler.handle(Re writeHandler.java:176)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:313)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:506)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:205)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
Caused by: com.zimbra.cs.mailbox.MailSender$SafeMessagingExce ption: Read timed out; chained exception is:
java.net.SocketTimeoutException: Read timed out
at com.sun.mail.smtp.SMTPTransport.readServerResponse (SMTPTransport.java:1598)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTra nsport.java:1356)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SM TPTransport.java:399)
at javax.mail.Service.connect(Service.java:275)
at javax.mail.Service.connect(Service.java:156)
at javax.mail.Service.connect(Service.java:105)
at javax.mail.Transport.send0(Transport.java:168)
at javax.mail.Transport.send(Transport.java:98)
at com.zimbra.cs.mailbox.MailSender.sendMessage(MailS ender.java:428)
at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:248)
... 33 more