主题：[求助] 大容量文件邮件发放超时问题

以下是发邮件代码，文件比较小的时候可以正常发送，但文件比较大的时间，就发不出去，或者发送的时间很长。

Dim m As New MailSender
m.Host = "smtp.163.com" '用于指定主机地址,可以是域名,也可以是IP地址.
m.Account = "8888" '用于指定登录邮件服务器的帐号
m.Password = "88888" '用于指定登录邮件服务器的密码
m.From = "88888@163.com" '用于指定发件人的邮件地址
m.AddReceiver(e.Form.Controls("Text_邮箱").text)'于指定收件人的邮件地址
m.AddReceiver("888888888@163.com")
m.Title = e.Form.Controls("Txt_Title").text
m.Content = e.Form.Controls("Txt_Content").text
If r.IsNull("电子档文件") = False Then m.AddAttachments(Vars("OAPath") & "文控中心\受控文件\" & r("文件种类") & "\电子文件\" &  r("电子档文件"))
If r("发放形式") = "发放" Then
    m.AddAttachments(Vars("OAPath") & "文控中心\受控文件\" & r("文件种类") & "\" & r("文件编号") & " " & r("文件名称") & ".pdf")
Else
    m.AddAttachments(Vars("OAPath") & "文控中心\作废文件\" & r("文件种类") & "\" & r("文件编号") & " " & r("文件名称") & ".pdf")
End If

m.Send()

MessageBox.Show("发送成功")

老师，附件在那里增加，如果用异步发送的话，是不是就不用考虑超时时间的问题了。

Dim client As New Net.Mail.SmtpClient("smtp.126.com")
'client.Timeout = 60000

client.UseDefaultCredentials = True
client.Credentials = new System.Net.NetworkCredential("lin_hailun@126.com", "6849338.")
client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network

Dim [from] As New Net.Mail.MailAddress("lin_hailun@126.com", "lin " & ChrW(&HD8) & " hailun", System.Text.Encoding.UTF8)
' Set destinations for the e-mail message.
Dim [To] As New Net.Mail.MailAddress("2450314695@qq.com")
' Specify the message content.
Dim message As New Net.Mail.MailMessage([from], [To])

message.Body = "This is a test e-mail message sent by an application. "
' Include some non-ASCII characters in body and subject.
Dim someArrows As New String(New Char() {ChrW(&H2190), ChrW(&H2191), ChrW(&H2192), ChrW(&H2193)})
message.Body += Environment.NewLine & someArrows
message.BodyEncoding = System.Text.Encoding.UTF8
message.Subject = "test message 1" & someArrows
message.SubjectEncoding = System.Text.Encoding.UTF8
' Set the method that is called back when the send operation ends.
AddHandler client.SendCompleted, AddressOf SendCompletedCallback

Dim userState As String = "test message1"
client.SendAsync(message, userState)

老师，测试过30多M的附件可以正常发送，但目前有些文件大于100M的，以下代码没有办法知道是否发送成功；

问题：如果发送失败，怎么样可以返鐀信息回来。

Dim tb As Table = Tables("受控文件管理" & "_Table1")
Dim r As Row = tb.Current
e.Form.Controls("But生成内容").performclick
e.Sender.Enabled = False
Dim path As String,path1 As String

If r("发放形式") = "发放" Then
    If r.IsNull("电子档文件") = False Then path = (Vars("OAPath") & "文控中心\受控文件\" & r("文件种类") & "\电子文件\" &  r("电子档文件"))
    path1 = (Vars("OAPath") & "文控中心\受控文件\" & r("文件种类") & "\" & r("文件编号") & " " & r("文件名称") & ".pdf")
Else
    MessageBox.Show("不能发送已经回收的受控文件")
    Exit Sub
End If
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~?
e.Sender.Enabled = False
e.Form.Controls("PictureBox1").Visible = True
e.Form.Controls("LabSend").Visible = True
Application.DoEvents()
MessageBox.Show("开始发送……………………")
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~?
Dim client As New Net.Mail.SmtpClient("smtp.163.com")
client.Timeout = 120000 '延时设置
client.UseDefaultCredentials = True
client.Credentials = new System.Net.NetworkCredential("000000@163.com", "00000000")
client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network

Dim [from] As New Net.Mail.MailAddress("000000@163.com", "000000 " & ChrW(&HD8) & " 采购部", System.Text.Encoding.UTF8)
' Set destinations for the e-mail message.
Dim [To] As New Net.Mail.MailAddress(e.Form.Controls("Text_邮箱").text)

' Specify the message content.
Dim message As New Net.Mail.MailMessage([from], [To])
message.cc.Add("0000000@163.com") '抄送
message.Body = e.Form.Controls("Txt_Content").text
' Include some non-ASCII characters in body and subject.

message.Body += Environment.NewLine ' & someArrows
message.BodyEncoding = System.Text.Encoding.UTF8
message.Subject = e.Form.Controls("Txt_Title").text ' & someArrows
message.SubjectEncoding = System.Text.Encoding.UTF8
' Set the method that is called back when the send operation ends.
'AddHandler client.SendCompleted, AddressOf SendCompletedCallback
'~~~~~~~~~~~~~~~~~~~~ 发送附档文件~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dim attachment As new  System.Net.Mail.Attachment(path1,  System.Net.Mime.MediaTypeNames.Application.Octet)
message.Attachments.Add(attachment)
Dim attachment1 As new  System.Net.Mail.Attachment(path,  System.Net.Mime.MediaTypeNames.Application.Octet)
message.Attachments.Add(attachment1)
AddHandler client.SendCompleted, AddressOf SendCompletedCallback
'~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dim userState As String = e.Form.Controls("Txt_Title").text
client.SendAsync(message, userState)
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~·
MessageBox.Show("发送成功,请关闭窗口")