C#写的smtp发送邮件不能正常显示Base64编码的问题

Question

最近开发中用了lion兄弟写的smtp邮件发送类，根据自己的需要适当做了点修改
邮件Subject和Body还有附件都以Base64编码
但接收到的邮件都是编码后的内容，一堆的垃圾字符，没有还原
求教高手指点迷津，感激不尽
付上一段代码（太长，放不完）
if(m_Charset=="") 
{ 
SendBufferstr+="Subject:" + m_Subject + enter; 
} 
else 
{ 
SendBufferstr+="Subject:" + "=?" + m_Charset.ToUpper() + "?B?" + Base64Encode(m_Subject) +"?=" +enter; 
}  SendBufferstr+="X-Priority:" + m_Priority + enter; 
SendBufferstr+="X-MSMail-Priority:" + m_Priority + enter; 
SendBufferstr+="Importance:" + m_Priority + enter; 
SendBufferstr+="X-Mailer: Huolx.Pubclass" + enter; 
SendBufferstr+="MIME-Version: 1.0" + enter;  SendBufferstr += "Content-Type: multipart/mixed;"+enter;//内容格式和分隔符 
SendBufferstr += " boundary=\"----=_NextPart_000_00D6_01C29593.AAB31770\""+enter; 
SendBufferstr += "------=_NextPart_000_00D6_01C29593.AAB31770"+enter;  if(m_BodyFormat == MailFormat.Html) 
{ 
SendBufferstr+="Content-Type: text/html;" + enter; 
} 
else 
{ 
SendBufferstr+="Content-Type: text/plain;" + enter; 
}  if(m_Charset=="") 
{ 
SendBufferstr+=" charset=\"iso-8859-1\"" + enter; 
} 
else 
{ 
SendBufferstr+=" charset=\"" + m_Charset.ToLower() + "\"" + enter; 
}  SendBufferstr+="Content-Transfer-Encoding: base64" + enter + enter;  SendBufferstr+= Base64Encode(m_Body) + enter; 
//SendBufferstr+= "=?" + m_Charset.ToUpper() + "?B?" + Base64Encode(m_Body) +"?=" + enter;
if(m_Attachments.Count!=0) 
{ 
foreach(string filepath in m_Attachments) 
{ 
if( File.Exists(filepath ) )
{
SendBufferstr += "------=_NextPart_000_00D6_01C29593.AAB31770"+enter; 
SendBufferstr += "Content-Type: application/octet-stream"+enter; 
SendBufferstr += " name=\"=?"+m_Charset.ToUpper()+"?B?"+Base64Encode(filepath.Substring(filepath.LastIndexOf("\\")+1))+"?=\""+enter; 
SendBufferstr += "Content-Transfer-Encoding: base64"+enter; 
SendBufferstr += "Content-Disposition: attachment;"+enter; 
SendBufferstr += " filename=\"=?"+m_Charset.ToUpper()+"?B?"+Base64Encode(filepath.Substring(filepath.LastIndexOf("\\")+1))+"?=\""+enter+enter; 
SendBufferstr += GetByes(filepath)+enter+enter; 
}
} 
} 

SendBufferstr += "------=_NextPart_000_00D6_01C29593.AAB31770--"+enter+enter;  SendBufferstr += enter + "." + enter;

Answer 1

public   static   byte[]   Base64Encode(byte[]   source)
{

if((source==null)||(source.Length   ==0))
throw   new   ArgumentException("source   is   not   valid"); ToBase64Transform   tb64   =   new   ToBase64Transform();
MemoryStream   stm   =   new   MemoryStream();
int   pos   =   0;
byte[]   buff; while   (pos   +   3   <   source.Length)   
{
buff   =   tb64.TransformFinalBlock   (source,   pos,   3);
stm.Write   (buff,   0,   buff.Length);
pos   +=   3;
} buff   =   tb64.TransformFinalBlock   (source,   pos,   source.Length   -   pos);
stm.Write   (buff,   0,   buff.Length); return   stm.ToArray();
}