I have no idea why your server is complaining about php_sybase_ct.dll since osTicket doesn't use it.
I do not have it installed or enabled on my installations.
Your error does not appear to being generated from osTicket at all.
I've never seen anyone else running osTicket with this specific error before either.
Maybe try uninstalling PHP and installing a different version?
I may end up having to try a different PHP version. I removed all referenced to sybase in the php.ini and ensure that it disabled it. and tested SMTP email again and still 500 error. But the sybase errors are gone now. however I do not get anything in the system logs now to point me in the right direction.