error while compiling log4j

[Mac Smith]

Hi,

I am getting this error while compiling log4j

# gcj -c -fjni log4j.jar -o log4j.oorg/apache/log4j/net/SMTPAppender.java:0: error: cannot find file for class javax.mail.Authenticator
org/apache/log4j/net/SMTPAppender.java:0: error: cannot find file for class javax.mail.Authenticator
org/apache/log4j/net/SMTPAppender.java:183: confused by earlier errors, bailing out


my gcj verison is

gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) on Ubuntu 9.04


--
Mac