在VB.net上发送电子邮件

Question

谁能帮我。 我创建了一个电子邮件程序。 单击发送按钮时出现错误。 这是我的代码：

Imports System.Net.Mail

Public Class frmEmail
Dim emailaddress As String
Dim password As String
Dim port As Integer
Dim host As String

Private Sub frmEmail_Load(sender As Object, e As EventArgs)

 If emailaddress.ToLower.Contains("@gmail") Then
        port = 587
        host = "smtp.gmail.com"
    ElseIf emailaddress.ToLower.Contains("@yahoo") Then
        port = 465
        host = "smtp.mail.yahoo.com"
    End If

End Sub

Private Sub btnSend_Click(ByVal sender As Object, ByVal e As    EventArgs) Handles btnSend.Click
    Try
        Dim smtpServer As New SmtpClient
        Dim mail As New MailMessage()
        smtpServer.Credentials = New Net.NetworkCredential(emailaddress, password)
        smtpServer.Port = port
        smtpServer.Host = host
        smtpServer.EnableSsl = True
        mail = New MailMessage()
        mail.From = New MailAddress(emailaddress)
        mail.To.Add(txtTo.Text)
        mail.Subject = txtSubject.Text
        mail.Body = txtMessage.Text
        smtpServer.Send(mail)
        MsgBox("The mail is send!", MsgBoxStyle.Information)
    Catch error_t As Exception
        MsgBox(error_t.ToString)
    End Try
End Sub
End Class

而且我遇到了以下错误：System.ArgumentOutOfRangeException：指定的参数不在有效值范围内。 参数名称：System.Net.Mail.SmtpClient.set_Port处的值（Int32值）

***编辑忘记将其修改为原始代码

Answer 1

您的子私人子frmEmail_Load（作为对象发送，作为EventArgs发送）

窗体加载时不运行。

由于此port设置为默认值0

您需要告诉VB.Net在表单加载时运行，如下所示

Private Sub frmEmail_Load(sender As Object, e As EventArgs) Handles MyBase.Load

同样在代码下方，您可能会发现从电子邮件服务器收到有关身份验证的错误。 如果得到这个，就在下面

Dim smtpServer As New SmtpClient

加上这个

smtpServer.UseDefaultCredentials = False

它可能会起作用。