When sending an email from APM CE (CEM), getting "Error: The email could not be sent: Sending the email to the following server failed : <server_name>.com:25."
In the MOM log, the following error message appears:
org.apache.commons.mail.EmailException: Sending the email to the following server failed : <server_name>.com:25:501 Syntax: HELO hostname
The 501 error message notes when there is a syntax error with the parameters or arguments. In this case, the email server cannot process the SMTP command "HELO hostname", so APM CE (CEM) is unable to send the email.
To typically resolve this issue, check that the domain name lookup is correctly configured.
The domain name of the TESS-MOM machine must be "hostname." To determine if this is correct, do a reverse domain name lookup.
The following is an example of how to do the equivalent operation with telnet:
[root@sustaining1 ~]# telnet mail.ca.com 25
Connected to mail.ca.com (10.10.10.10).
Escape character is '^]'.
220 smtp1.ca.com Authorized Users Only! Wed, 15 Oct 2013 14:09:33 -0400
250 smtp1.ca.com Hello