I get this error message when a new user tries to register. He has to press back on the browser to go back and send confirmation email. And he stays logged in. Anyway to deal with this. 

Error 500
Internal Server Error.

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Something went wrong!
To get the error details follow these steps:
- Open ow_includes/config.php file and set DEBUG_MODE to true
- Reproduce your last action.Error details:Type:ExceptionMessage:Could not instantiate mail function.File:/home4/studepn8/public_html/ow_libraries/vendor/phpmailer/phpmailer/class.phpmailer.phpLine:1451Trace:#0 /home4/studepn8/public_html/ow_libraries/vendor/phpmailer/phpmailer/class.phpmailer.php(1323): PHPMailer->mailSend('Date: Mon, 20 J...', 'This is a multi...') #1 /home4/studepn8/public_html/ow_libraries/vendor/phpmailer/phpmailer/class.phpmailer.php(1201): PHPMailer->postSend() #2 /home4/studepn8/public_html/ow_system_plugins/base/bol/mail_service.php(272): PHPMailer->send() #3 /home4/studepn8/public_html/ow_core/mailer.php(97): BOL_MailService->send(Object(BASE_CLASS_Mail)) #4 /home4/studepn8/public_html/ow_system_plugins/base/bol/email_verify_service.php(230): OW_Mailer->send(Object(BASE_CLASS_Mail)) #5 /home4/studepn8/public_html/ow_system_plugins/base/bol/email_verify_service.php(258): BOL_EmailVerifyService->sendVerificationMail('user', Array) #6 /home4/studepn8/public_html/ow_system_plugins/base/controllers/join.php(318): BOL_EmailVerifyService->sendUserVerificationMail(Object(BOL_User)) #7 /home4/studepn8/public_html/ow_system_plugins/base/controllers/join.php(218): BASE_CTRL_Join->joinUser(Array, '290365aadde35a9...', Array) #8 /home4/studepn8/public_html/ow_system_plugins/base/controllers/join.php(170): BASE_CTRL_Join->postProcess(Array) #9 [internal function]: BASE_CTRL_Join->joinFormSubmit(Array) #10 /home4/studepn8/public_html/ow_core/request_handler.php(276): ReflectionMethod->invokeArgs(Object(BASE_CTRL_Join), Array) #11 /home4/studepn8/public_html/ow_core/request_handler.php(252): OW_RequestHandler->processControllerAction(Object(ReflectionMethod), Object(BASE_CTRL_Join)) #12 /home4/studepn8/public_html/ow_core/application.php(364): OW_RequestHandler->dispatch() #13 /home4/studepn8/public_html/index.php(76): OW_Application->handleRequest() #14 {main}