我有一个用C＃编写的应用程序。在这个应用程序中，我将在服务器上动态创建一个excel并将列表写入excel并将此excel附加到Email中并将此excel发送给用户。
最近，我观察到如果列表计数超过20,000，则Mails不会转到用户。
如果列表计数小于20,000，则会成功触发电子邮件。
我正在使用DocumentFormat.Openxml.dll
当我查看事件日志时，我看到以下错误
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 6/11/2013 5:29:52 PM
Event time (UTC): 6/11/2013 9:29:52 PM
Event ID: 74a095c641ac424cb7b00f900028bc59
Event sequence: 50
Event occurrence: 1
Event detail code: 0
Application information:
Application domain: XXXXXX
Trust level: Full
Application Virtual Path:XXXXX
Application Path: XXXXXXXX
Machine name: XXXXXXX
Process information:
Process ID: 15352
Process name: w3wp.exe
Account name: NT AUTHORITY\NETWORK SERVICE
Exception information:
Exception type: NullReferenceException
Exception message: Object reference not set to an instance of an object.
Request information:
Request URL: XXXXXXXXXXXXXXXXXXX
Request path: XXXXXXXXXXXXXXXXX
User host address: XXXXXXXXXX
User: XXXXXXXXXXXXXXXX
Is authenticated: True
Authentication Type: Forms
Thread account name: NT AUTHORITY\NETWORK SERVICE
Thread information:
Thread ID: 1
Thread account name: NT AUTHORITY\NETWORK SERVICE
Is impersonating: False
Stack trace: at btnSendNotification_Click(Object sender, EventArgs e)
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
Custom event details:
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.