Target server problems

Table 1. Common messages indicating target server status
Symptoms	Problem/Cause	Action
EZD1817I	This message indicates that the application has been unable to successfully connect to the target server at the indicated IP address due to a socket connect() failure or timeout.	For details and other messages, see the appropriate EZD1817I message in z/OS Communications Server: IP Messages Volume 2 (EZB, EZD).
EZD1818I	This message indicates that the application has been unable to communicate successfully with the target server at the indicated IP address due to an SMTP protocol problem or timeout after a successful connect. SMTP protocol problems can be the following: Initial SMTP greeting not sent 4xx or 5xx reply codes sent on EHLO SMTP command 4xx or 5xx reply codes sent on HELO SMTP command Other problems are socket read() or write() failures on the connection.	For details and other messages, see the appropriate EZD1818I message in z/OS Communications Server: IP Messages Volume 2 (EZB, EZD). If the problem appears to be in communicating with a target server, setting the loglevel to at least 39 will help to capture TCP/IP traces that show SMTP commands and remote SMTP server replies between the CSSMTP application and the TCP/IP network.
EZD1819I	This message indicates that the application has been unable to establish a TLS connection with the target server at the indicated IP address due to an SMTP protocol problem, a security certificate problem or a timeout. SMTP protocol problems can have the following causes: STARTTLS option not supported on EHLO SMTP command 4xx or 5xx reply codes sent on STARTTLS SMTP command The stack does not support TLS policies. The policy agent is not started resulting in SIOCTTLSCTL ioctl() failures. Socket read() or write() failures on the connection.	For details and other messages, see the appropriate EZD1819I message in z/OS Communications Server: IP Messages Volume 2 (EZB, EZD). For details setting up TLS security on the CSSMTP application, see z/OS Communications Server: IP Configuration Guide. If TLS is enabled and the definitions are configured on the client stacks but EZD1819I and log file ERROR messages indicates this is due to security see Diagnosing Application Transparent Transport Layer Security (AT-TLS). If TLS is set up correctly on CSSMTP, then verify that TLS is set up correctly on the server.
EZD1820E	This message indicates that no target server is capable of receiving mail. There may be a networking problem affecting all target servers. Processing of mail is suspended when this message is generated.	For details and other messages, see the appropriate EZD1820E message in z/OS Communications Server: IP Messages Volume 2 (EZB, EZD).
EZD1824E	This message indicates that the application has been unable to successfully communicate to the TCP/IP stack as the result of a socket() failure. Processing of mail is suspended when this message is generated.	For details and other messages, see the appropriate EZD1824E message in z/OS Communications Server: IP Messages Volume 2 (EZB, EZD).