How to add thirdparty jars as Bootstrap entries to jvm in ANT script while building project using bamboo

I have added activation.jar & mail.jar's path under Bootstrap entries of run configuration in eclipse. I have done so because I was facing NoClassDefError for javax.activation.DataSource even though I have added it in my project classpath. Also didn't see any compilation issues for code where I used DataSource and other classes from these jars. I tried all solutions listed suggested on stackoverflow but nothing worked for me and finally I got this Bootstrap entries option which resolved my issue.

Now the problem is I wanted to create build using Bamboo and I have mentioned required jars in launcher ANT script as below:

<target>
    <java jvm="${javaHome}/bin/java.exe"
    <!--some other parameters ->
    >
            <classpath>
                <fileset dir="${buildDir}/scripts/lib">
                    <include name="mail.jar"/>
                    <include name="activation.jar"/>
                </fileset>
            </classpath> 
    </java>
    </target>

Still I am getting same activation error in generated build application. I am very new to ANT. Please suggest how can resolve above issue.

Thanks!