mail task results in authentication failure when using gmail as smtp server

To whom it may concern,
        I am trying to use gmail as an smtp server with the ant mail task.
I have set up the task as follows:


<mail

         user="e-mail address"

         password="password"

         ssl="yes"

         mailhost="smtp.gmail.com"

         mailport="465"

         subject="Nightly unit test results">

         <to address="e-mail address" />

         <from address="e-mail address" />

         <message src="/Directory/On/My/Machine" />

</mail>


This worked a few months ago, but these days, when I run my ant build file
I get the follow error:


Failed to send email: 534-5.7.14 <
https://accounts.google.com/ContinueSignIn?sarp=1&scc=1&plt=AKgnsbtAR

     [mail] 534-5.7.14
Xr2YD-ghKP2iyh466DE7nVr1n5WwF5lf7k8MZzGM9T0VI3UPNNsjR5PyjPoJtKhjlVBPSo

     [mail] 534-5.7.14
QTLSBT8z20kqwuU1vVfnG1Bg0dheJTuXClSawq1aReyb47UeIFbXqvr2l_2JjEwe3eXJAh

     [mail] 534-5.7.14
5tgRqrzCiTDdCwJRm-Tgk7h3uKvQ4u_yPW6da7yORpot1RULSt4Sb3xk_GErdyZbmuurF9

     [mail] 534-5.7.14 ILExbCY-gsmeNMVjcx55lv4ZOczA> Please log in via your
web browser and

     [mail] 534-5.7.14 then try again.

     [mail] 534-5.7.14 Learn more at

     [mail] 534 5.7.14
https://support.google.com/mail/bin/answer.py?answer=78754
n34sm1388141qge.27 - gsmtp

Do I need to loosen the security settings on my gmail account or are there
other properties I need to set in the mail task to prevent the
authentication error?

Thanks,

Jason Mazzotta