Email notifications problem

I tested the email using the test smpt button and it works. But I keep getting this error when a cron job is run

Event Details
Type: Errors
Severity:Error
Date:11/19/2012 3:00 pm
Message:
Unhandled phpmailerException: SMTP Error: Could not authenticate. in /home/content/v/s/e/vseuylem1/html/webissues/system/mail/class.phpmailer.php on line 872
Stack trace:
#0 /home/content/v/s/e/vseuylem1/html/webissues/system/mail/class.phpmailer.php(763): PHPMailer->SmtpConnect()
#1 /home/content/v/s/e/vseuylem1/html/webissues/system/mail/class.phpmailer.php(630): PHPMailer->SmtpSend('Date: Mon, 19 N...', '?? ...')
#2 /home/content/v/s/e/vseuylem1/html/webissues/system/mail/class.phpmailer.php(575): PHPMailer->PostSend()
#3 /home/content/v/s/e/vseuylem1/html/webissues/system/mail/engine.inc.php(112): PHPMailer->Send()
#4 /home/content/v/s/e/vseuylem1/html/webissues/cron/job.php(157): System_Mail_Engine->send('varoujs@gmail.c...', 'Administrator', 'WMS_EZInventory...', '?? ...')
#5 /home/content/v/s/e/vseuylem1/html/webissues/cron/job.php(73): Cron_Job->sendNotificationEmails()
#6 /home/content/v/s/e/vseuylem1/html/webissues/system/core/application.inc.php(210): Cron_Job->execute()
#7 /home/content/v/s/e/vseuylem1/html/webissues/system/bootstrap.inc.php(124): System_Core_Application->run()
#8 /home/content/v/s/e/vseuylem1/html/webissues/cron/job.php(191): System_Bootstrap::run('Cron_Job')
#9 {main}

User name:Administrator
Host name:unknown