如何在vb.net windows应用程序2010中通过smtp服务器使用gmail凭据发送电子邮件

我试图在我的VB.NETWindows应用程序（VS2010）中发送电子邮件，但我收到了

找不到SMTP主机

我的代码如下：

Dim SmtpServer As New SmtpClient()
SmtpServer.Credentials = New Net.NetworkCredential("mymailid@gmail.com", "mypassword")
SmtpServer.Port = 25
SmtpServer.Host = "smtp.gmail.com"
SmtpServer.EnableSsl = True
mail = New MailMessage()
Dim addr() As String = TextBox1.Text.Split(",")
Try
   mail.From = New MailAddress("mymailid@gmail.com", "Developers", System.Text.Encoding.UTF8)
   Dim i As Byte
   For i = 0 To addr.Length - 1
       mail.To.Add(addr(i))
   Next
   mail.Subject = TextBox3.Text
   'mail.Body = TextBox4.Text
   If ListBox1.Items.Count <> 0 Then
      For i = 0 To ListBox1.Items.Count - 1
          mail.Attachments.Add(New Attachment(ListBox1.Items.Item(i)))
      Next
   End If
   SmtpServer.SendAsync(mail, mail.Subject)

Dim SmtpServer作为新的SmtpClient（）
SmtpServer.Credentials=新的Net.NetworkCredential（“mymailid@gmail.com“，“我的密码”）
SmtpServer.Port=25
SmtpServer.Host=“smtp.gmail.com”
SmtpServer.EnableSsl=True
mail=新邮件消息（）
Dim addr（）作为字符串=TextBox1.Text.Split（“，”）
尝试
mail.From=新邮件地址（“mymailid@gmail.com，“开发者”，System.Text.Encoding.UTF8）
作为字节的Dim i
对于i=0，添加长度-1
邮寄至地址（地址（一））
下一个
mail.Subject=TextBox3.Text
'mail.Body=TextBox4.Text
如果ListBox1.Items.Count为0，则
对于ListBox1.Items.Count-1的i=0
mail.Attachments.Add（新附件（ListBox1.Items.Item（i）））
下一个
如果结束
SmtpServer.SendAsync（邮件、邮件、主题）

尝试将

SmtpServer.Port

设置为587

Dim SmtpServer As New SmtpClient("smtp.gmail.com", 587)
Dim mail As New MailMessage("sender address", "destination address", "subject", "body")
SmtpServer.Credentials = New Net.NetworkCredential("username/sender address","password")
SmtpServer.Send(Mail)

---

为了进行测试，我快速编写了这段代码，成功地发送了 发电子邮件到我的测试帐户。仅供参考，我已将第二个参数作为Nothing发送 在SmtpServer.SendAsync函数中。我想您可以快速了解如何在异步环境中实现它

试一试

请试一试

 Dim SmtpServer As New SmtpClient("smtp.gmail.com", 465)
 SmtpServer.EnableSsl = True
 SmtpServer.Credentials = New Net.NetworkCredential("name@gmail.com", "password")
 Dim mail As New MailMessage("name@gmail.com", "name@gmail.com", title, content)
 SmtpServer.Send(mail)

---

我不认为端口号本身是这里的问题-25应该起作用。不过，可能是防火墙阻止了它。优秀资源：请对您的答案进行解释

 Dim SmtpServer As New SmtpClient("smtp.gmail.com", 465)
 SmtpServer.EnableSsl = True
 SmtpServer.Credentials = New Net.NetworkCredential("name@gmail.com", "password")
 Dim mail As New MailMessage("name@gmail.com", "name@gmail.com", title, content)
 SmtpServer.Send(mail)

Imports System.Net.Mail
Public Class Form1
   Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
      ' Set the caption bar text of the form.   
      Me.Text = "tutorialspoint.com"
   End Sub

   Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
      Try
          Dim Smtp_Server As New SmtpClient
          Dim e_mail As New MailMessage()
          Smtp_Server.UseDefaultCredentials = False
          Smtp_Server.Credentials = New Net.NetworkCredential("username@gmail.com", "password")
          Smtp_Server.Port = 587
          Smtp_Server.EnableSsl = True
          Smtp_Server.Host = "smtp.gmail.com"

          e_mail = New MailMessage()
          e_mail.From = New MailAddress(txtFrom.Text)
          e_mail.To.Add(txtTo.Text)
          e_mail.Subject = "Email Sending"
          e_mail.IsBodyHtml = False
          e_mail.Body = txtMessage.Text
          Smtp_Server.Send(e_mail)
          MsgBox("Mail Sent")

      Catch error_t As Exception
          MsgBox(error_t.ToString)
      End Try

   End Sub
'Ghaffari