testing email

[Frogman]

Mailer Validation Error: Failed to authenticate on SMTP server with username "byteoptics@tuneitpro.com" using the following authenticators: "LOGIN", "PLAIN". Authenticator "LOGIN" returned "Expected response code "235" but got code "535", with message "535 Incorrect authentication data".". Authenticator "PLAIN" returned "Expected response code "235" but got code "535", with message "535 Incorrect authentication data".".
#0 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/EsmtpTransport.php(177): Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport->handleAuth()
#1 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/EsmtpTransport.php(134): Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport->doEhloCommand()
#2 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/SmtpTransport.php(255): Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport->executeCommand()
#3 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/SmtpTransport.php(281): Symfony\Component\Mailer\Transport\Smtp\SmtpTransport->doHeloCommand()
#4 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/SmtpTransport.php(211): Symfony\Component\Mailer\Transport\Smtp\SmtpTransport->start()
#5 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/AbstractTransport.php(69): Symfony\Component\Mailer\Transport\Smtp\SmtpTransport->doSend()
#6 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Transport/Smtp/SmtpTransport.php(138): Symfony\Component\Mailer\Transport\AbstractTransport->send()
#7 /home/tunei960/billing3.tuneitpro.com/vendor/symfony/mailer/Mailer.php(38): Symfony\Component\Mailer\Transport\Smtp\SmtpTransport->send()
#8 /home/tunei960/billing3.tuneitpro.com/core/lib/mail.php(332): Symfony\Component\Mailer\Mailer->send()
#9 /home/tunei960/billing3.tuneitpro.com/admin/controller/pages/setting/setting.php(768): AMail->send()
#10 /home/tunei960/billing3.tuneitpro.com/admin/controller/pages/setting/setting.php(65): ControllerPagesSettingSetting->_validate()
#11 /home/tunei960/billing3.tuneitpro.com/core/engine/dispatcher.php(308): ControllerPagesSettingSetting->main()
#12 /home/tunei960/billing3.tuneitpro.com/core/engine/dispatcher.php(343): ADispatcher->dispatch()
#13 /home/tunei960/billing3.tuneitpro.com/core/engine/page.php(110): ADispatcher->dispatch()
#14 /home/tunei960/billing3.tuneitpro.com/core/engine/router.php(204): APage->build()
#15 /home/tunei960/billing3.tuneitpro.com/core/engine/router.php(86): ARouter->route()
#16 /home/tunei960/billing3.tuneitpro.com/index.php(95): ARouter->processRoute()
#17 {main}
why is this not working, have the exact same settings in v1.3.4, setting up v1.4.2 on same server but email is failing. And running php v8.3 Need some help!

[Basara]

Hello.
You're encountering this SMTP authentication error: 535 Incorrect authentication data

which means the SMTP server is rejecting the credentials you're providing