二。Exchange服务器症状：
1.exchange服务器重启后在登录界面出现错误提示“Service Control Manager:At least one service or driver failed during system startup.Use Event Viewer to examine the event log for details”，
2.打开服务管理器，发现Microsoft Exchange Information Store和Microsoft Exchange MTA Stacks两个服务的启动类型是“automatically”却不能自动启动。
3.下边是服务器日志中的一些错误：
1)Source:Kerberos;Category:None;Type:Error;Event ID:5; Description:The kerberos client received a KRB_AP_ERR_TKT_NYV error from the server host/ptcnsql.ptchina.local. This indicates that the ticket used against that server is not yet valid (in relationship to that server time). Contact your system administrator to make sure the client and server times are in sync, and that the KDC in realm PTCHINA.LOCAL is in sync with the KDC in the client realm.
2)Source:MSExchangeIS; category:General;Type:Error;Event Id:5003;Description:Unable to initialize the Microsoft Exchange Information Store service because the clocks on the client and on the server machine are skewed. This may be caused by a time change either in the client or the server machine, and may require a reboot of that machine. Other than that, verify that your domain is properly configured and is currently online.
3)Source:smtpsvc;Category:None;Type:Error;Event Id:2013;Description:SMTP could not connect to any DNS server. Either none are configured, or all are down.
4)Source: Service Control Manager;Category:None;Type:Error;Event ID:7024;Description:The Microsoft Exchange Information Store service terminated with service-specific error 0 (0x0).
5)Source:smtpsvc;EventID:2012Type:Warning;Description:SMTP could not connect to the DNS server '192.168.1.3'. The protocol used was 'UDP'. It may be down or inaccessible.
6)Source:MSExchangeIS Mailbox Store;EventID:2000;Category:MTA onnections;Type:Warning;Description:Verify that the Microsoft Exchange MTA service has started. Consecutive ma-open calls are failing with error 3051.
7)Source:MSExchangeIS;EventID:9665;Type:Warning;Description:The memory settings for this server are not optimal for Exchange.
刚开始以为是网络有问题，不能到达或解析邮件服务器，在客户端试过用主机名都能ping通。实验发现如果重新启动Microsoft Exchange Information Store服务，可能会好用一会。
在网上查了很多文章，都不起作用，比如：
1.脱机重新启动 Microsoft Outlook，然后按 F9 执行同步。 （会重新提示输入用户名和密码）
2.客户端注册表\\HKLM\Software\Microsoft\RPC\ClientProtocols中注册Rpcrt4.dll。 （本来就有）
