javamail问题

用eclipse实现javamail,eclipse里明明就有javax.mail包，但是运行的时候出现
麻烦大家帮我看看是怎么一回事org.apache.jasper.JasperException: Unable to compile class for JSPGenerated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:7: package javax.mail does not exist
import javax.mail.*;
^
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:8: package javax.mail.internet does not exist
import javax.mail.internet.*;
^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:83: cannot resolve symbol
symbol  : class Session 
location: class org.apache.jsp.sendmail_jsp
Session s=Session.getInstance(props);//鏍规嵁灞炴?ф柊寤轰竴涓偖浠朵細璇?
^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:83: cannot resolve symbol
symbol  : variable Session 
location: class org.apache.jsp.sendmail_jsp
Session s=Session.getInstance(props);//鏍规嵁灞炴?ф柊寤轰竴涓偖浠朵細璇?
          ^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:87: cannot resolve symbol
symbol  : class MimeMessage 
location: class org.apache.jsp.sendmail_jsp
MimeMessage message=new MimeMessage(s);//鐢遍偖浠朵細璇濇柊寤轰竴涓秷鎭璞?
^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:87: cannot resolve symbol
symbol  : class MimeMessage 
location: class org.apache.jsp.sendmail_jsp
MimeMessage message=new MimeMessage(s);//鐢遍偖浠朵細璇濇柊寤轰竴涓秷鎭璞?
                        ^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:90: cannot resolve symbol
symbol  : class InternetAddress 
location: class org.apache.jsp.sendmail_jsp
InternetAddress from=new InternetAddress("[email protected]");
^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:90: cannot resolve symbol
symbol  : class InternetAddress 
location: class org.apache.jsp.sendmail_jsp
InternetAddress from=new InternetAddress("[email protected]");
                         ^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:92: cannot resolve symbol
symbol  : class InternetAddress 
location: class org.apache.jsp.sendmail_jsp
InternetAddress to=new InternetAddress(to_mail);
^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:92: cannot resolve symbol
symbol  : class InternetAddress 
location: class org.apache.jsp.sendmail_jsp
InternetAddress to=new InternetAddress(to_mail);
                       ^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:93: package Message does not exist
message.setRecipient(Message.RecipientType.TO,to);//璁剧疆鏀朵欢浜?,骞惰缃叾鎺ユ敹绫诲瀷涓篢O
                            ^
An error occurred at line: 27 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:100: cannot resolve symbol
symbol  : class Transport 
location: class org.apache.jsp.sendmail_jsp
Transport transport=s.getTransport("smtp");
^
An error occurred at line: 64 in the jsp file: /sendmail.jsp
Generated servlet error:
G:\Tomcat 5.0\work\Catalina\localhost\javamail\org\apache\jsp\sendmail_jsp.java:111: cannot resolve symbol
symbol  : class MessagingException 
location: class org.apache.jsp.sendmail_jsp
}catch(MessagingException e){