What version of JavaMail are you using?
If you examine the debug output, does it show JavaMail authenticating to your server?
Is the SMTPAuth parameter passed in as "1"?
You might need to change Session.getDefaultInstance to Session.getInstance.
If none of that solves your problem, see this FAQ entry:
In the mail.jar file, in META-INF/MANIFEST.MF, there will be version information. If there is no version information,
you have a very old version and should definitely upgrade. Get the latest version at http://javamail.java.net.
How to turn on debugging:
I know nothing about PL/SQL so I can't help you there.
If you didn't install JavaMail to begin with, you may need to find the person who did
and ask them for help.
Javamail is installed with the Oracle 11G, not installed alone
This is the METAINF
SCCS-ID: @(#)javamail.mf 1.4 00/09/26
Specification-Title: JavaMail(TM) API Design Specification
Specification-Vendor: Sun Microsystems, Inc.
Implementation-Vendor: Sun Microsystems, Inc.
Edited by: user10601354 on 23-abr-2013 13:00