Solved How to debug the error?
emails are not working(not getting email notification to customer/agent/admin) after setting my all swiftmailer and email setting.
Locate the file vendor->uvdesk->core-framework->Services->EmailService.php.
Open the EmailService.php reach to sendMail() function.
and dump() the exception as in attached image.
It will show the error you are facing while sending mails (if adding an agent, creating a ticket etc).
@Sanjeev thanks for your quick response!!
preg_split() expects parameter 2 to be string, array given - this is the exception I am getting after adding code to print exception while sending email
Please add red mark lines in code as attached in below screenshot.