so to make sure that the mail server is working i tried sending mail to local address
which is firstname.lastname@example.org it works
but when i try to send mail to external address it get error listed above.
so i added my email email@example.com to gmail to test whether the mail server is working correctly from gmail i can send email from firstname.lastname@example.org and recieve both but when i try that from my server it doesnot work
my server is offshore and i am using enom mail server to send email