Use ESMTP (SMTP) for mail sending

When ESMTP/SMTP is used for mail sending, a problem occurs:
If the attachment is an image gif file, there is no problem with sending it. However, after receiving the message, the image cannot be displayed. Please kindly advise !!!!!
/*
* Created on 2004-12-21
*
* TODO To change the template for this generated file go
* Window-Preferences-Java-Code Style-Code Templates
*/
/**
* @ Author Administrator
*
* TODO To change the template for this generated type comment go
* Window-Preferences-Java-Code Style-Code Templates
*/
Public class FoxMailMain {
Public static void main (String [] args ){

FoxMail foxMail = new FoxMail ("smtp.citiz.net", 25 );
FoxMail. setMailUserName ("zhou ");
FoxMail. setMailUserPass ("abcdefg ");
FoxMail. setMailTo ("aaaaa@citiz.net ");
FoxMail. setMailFrom ("bbbb@citiz.net ");
FoxMail. setMailShowTo ("tom ");
FoxMail. setMailShowFrom ("Nike ");
FoxMail. setMailSubject ("hello Chinese topic ");
FoxMail. setMailBody ("welcome for you. mmm. Chinese ah. aaa uploads a line ");
FoxMail. setMailAttachFile (new String [] {"D: eclipse_projectworkspacePROJECT_emailsrcpic.gif "});

If (foxMail. sendMail ()){
System. out. println ("OK .");
} Else {
System. out. println ("False .");
}
}
}
FoxMail. java code
Import java. io. File;
Import java. io. FileInputStream;
Import java. io. FileNotFoundException;
Import java. io. IOException;
Import java. io. InputStream;
Import java. io. OutputStream;
Import java.net. Socket;
Import java. text. DateFormat;
Import java. text. SimpleDateFormat;
Import java. util. Date;
/*
* Created on 2004-12-21
*
* TODO To change the template for this generated file go
* Window-Preferences-Java-Code Style-Code Templates
*/
/**
* @ Author Administrator