gmail - SMTP authentication error while connecting to Gmail with oAuth2/JavaMail in web app

Question

I am able to run Google's sample code for Gmail IMAP/SMTP using JavaMail with oAuth on cmdline (OAuth2Authenticator.java from http://code.google.com/p/google-mail-oauth2-tools/)

But the same code doesn't seem to work for SMTP (IMAP works fine) in the web app on tomcat. It throws

535-5.7.1 Username and Password not accepted. Learn more at 535 5.7.1 http://support.google.com/mail/bin/answer.py?answer=14257

Any idea, why this doesn't work for SMTP alone on web app?