程序中要用到名称空间（NameSpace）—System.Web.Mail（在.NET Framework SDK Beta1版本中叫做System.Web.Util）类库里所提供的邮件发送的对象、属性和方法。

1、  对象（Object）

System.Web.Mail名称空间用来发送邮件的对象有SmtpMail、MailMessage和MailAttachment等三个对象，具体作用下文有说明。

2、  属性（Propertiy）

System.Web.Mail名称空间的主要属性，是MailMessage对象的属性，下表列出了MailMessage对象属性的名称及其意义：

属性名称                      代表意义

From                          发信人地址（源地址）

To                            接收人地址（目的地制）

Subject                        邮件标题

Priority                        邮件优先级（High,Low,Normal）

Attachment                     邮件附件

Bcc                           暗送地址

Cc                            抄送地址

Body                          邮件主体

BodyFormat                    邮件格式（Html格式、Text格式）

Bodyencoding                  编码（Base64,UUencode）

3、  方法（Method）

Send方法，邮件就是通过Send方法发送出去的。该方法的调用有两种方式：

1）  SmtpMail.Send(“源地址”,”目标地址”,”主题”,”内容”)

2）  SmtpMail.Send(MailMessage)

        '1.发送简单信件
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com"
        mail.From = "you@yourcompany.com"
        mail.Subject = "this is a test email."
        mail.Body = "this is my test email body"
        SmtpMail.SmtpServer = "localhost"        'your real server goes here
        SmtpMail.Send(mail)
        '这里的smtpserver只能是那些不需要验证的smtp服务器，像126,sina,yahoo等等的邮箱，都需要验证，所以不能用。用这些邮箱发信后面会讲到

        '2.发送html信件
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com"
        mail.From = "you@yourcompany.com"
        mail.Subject = "this is a test email."
        mail.BodyFormat = MailFormat.Html
        mail.Body = "this is my test email body.<br><b>this part is in bold</b>"
        SmtpMail.SmtpServer = "localhost"       'your real server goes hereSmtpMail.Send(mail)
        '3.发送附件
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com"
        mail.From = "you@yourcompany.com"
        mail.Subject = "this is a test email."
        mail.Body = "this is my test email body."
        Dim attachment As New MailAttachment(Server.MapPath("test.txt")) 'create the attachment
        mail.Attachments.Add(attachment) 'add the attachment
        SmtpMail.SmtpServer = "localhost" 'your real server goes here
        SmtpMail.Send(mail)
        '4，修改发件人和收件人的名称比如发件人的地址是abc@126.com,我们用outlook收到信，From一栏里将直接显示abc@126.com.能不能在From一栏里显示友好一点的名字呢？比如显示Tony Gong.
        Dim mail As New MailMessage
        mail.To = """John"" <me@mycompany.com>"
        mail.From = """Tony Gong"" <you@yourcompany.com>"
        mail.Subject = "this is a test email."
        mail.Body = "this is my test email body."
        SmtpMail.SmtpServer = "localhost" 'your real server goes here
        SmtpMail.Send(mail)

        '5,发送给多人
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com;him@hiscompany.com;her@hercompany.com"
        mail.From = "you@yourcompany.com"
        mail.Subject = "this is a test email."
        mail.Body = "this is my test email body."
        SmtpMail.SmtpServer = "localhost" 'your real server goes here
        SmtpMail.Send(mail)

        '6，用需要Smtp验证的邮箱发信
        '现在为了防止垃圾邮件(, 绝大部分Smtp服务器需要验证了)
        '发信方法如下:
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com"
        mail.From = "abc@126.com"
        mail.Subject = "this is a test email."
        mail.Body = "Some text goes here"
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1")   'basic authentication 
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc")   'set your username here 
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "Your Password")   'set your password here 
        SmtpMail.SmtpServer = "smtp.126.com" 'your real server goes here  
        SmtpMail.Send(mail)
         ‘7,修改smtp服务器的端口，以及使用SSL加密大部分smtp服务器的端口是25，但有些却不是同时，绝大部分Smtp服务器不需要SSL登陆，有些却需要比如Gmail，smtp端口是：465，同时支持SSL代码如下：
        Dim mail As New MailMessage
        mail.To = "me@mycompany.com"
        mail.From = "abc@126.com"
        mail.Subject = "this is a test email."
        mail.Body = "Some text goes here"
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1")  'basic authentication 
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc")  'set your username here 
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "Your Password")  'set your password here   
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport", 465)
        mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true")
        SmtpMail.SmtpServer = "smtp.126.com" 'your real server goes here
        SmtpMail.Send(mail)