I am getting alot of the following messages from an ISP when sending out emails. Is there any way to get more information from these ? Users are reporting that they are not receiving any emails?
Jul 5 17:02:50 smtp sendmail: r6592of7011232: to=, delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=168781, relay=mx12.example.com.com. [18.104.22.168], dsn=5.0.0, stat=Service unavailable
Is it possible to start running debug mode for sendmail?