VB.NET制作发送邮件的程序

[tamadgebi]

VB.NET制作的发送邮件的程序，各位高手知道我一下，给我一段完整的代码，顺便帮我看看我的代码哪不行？
Dim mail As New MailMessage()

mail.From = New MailAddress(txtfrom.Text)

mail.To.Add(Txtaccept.Text)

'设置邮件内容

mail.Subject = Txtsubject.Text

mail.Body = Txtcontent.Text

''设置电子邮件优先级

mail.Priority = MailPriority.High

'获取与此电子邮件传输的标头

mail.Headers.Add("YourCompany", "yourname")

mail.Headers.Add("YourLocation", "yourlocation")

Dim Mysmtp As New SmtpClient(TxtSMTP.Text)

If CheckBox1.Checked = True Then

Mysmtp.Credentials = New System.Net.NetworkCredential(Txtname.Text, Txtpassword.Text)

End If

Try

Mysmtp.Send(mail)

MsgBox("邮件已经发出，邮件已经发送到指定的邮件地址.", MsgBoxStyle.Information, "实例，创建邮件发送程序")

Catch ex As Exception

MsgBox(ex.Message, MsgBoxStyle.Critical, "抱歉。邮件发送失败")

End Try

[BitCoffee]

                '发送邮件的代码都差不多.主要还是看发送的邮箱支不支持smtp发送.
                '可以拿你的发送邮箱在outlook里面设置，看能否发送.
                '有些防火墙也会阻止发送的.
                Imports System.net.Mail

                Dim client As New System.Net.Mail.SmtpClient("smtp.sina.com")
                Dim fromaddress As New System.Net.Mail.MailAddress("abc.sina.com")
                Dim toaddress As New System.Net.Mail.MailAddress("xxx.sina.com")
                client.UseDefaultCredentials = False
                client.Credentials = New System.Net.NetworkCredential("abc.sina.com", "123456")
                client.DeliveryMethod = SmtpDeliveryMethod.Network
                client.Port = "25"
                Dim message As New System.Net.Mail.MailMessage()
                message.From = fromaddress
                message.Subject = "主题"
                message.Body = "正文"
                message.To = toaddress
                  message.Attachments.Add(New Attachment("附件地址"))
                message.BodyEncoding = System.Text.Encoding.GetEncoding("gb2312")
                message.IsBodyHtml = True
                client.Send(message)

[hansin]

名前空間　　SmtpClient


'送信者
Dim senderMail As String = "[e-mail]"
'宛先
Dim recipientMail As String = "[e-mail]"
'件名
Dim subject As String = "こんにちは"
'本文
Dim body As String = "こんにちは。" + vbCrLf + vbCrLf + "それではまた。"

Dim sc As New System.Net.Mail.SmtpClient()
'SMTPサーバーを指定する
sc.Host = "localhost"
'メールを送信する
sc.Send(senderMail, recipientMail, subject, body)