The MSSQL_JOB job was defined with the USER parameter in order to override the value set in the <database_name>.properties file.
Upon the job submitting, the error "Login failed for user" was return, however the same user/password defined in the <>.properties file allowed successful job execution.
CAWA EE (ESP), CAWA Agent for MS SQL server
The cause of the issue was that the USER parameter in the job was defined with accordance to the Windows domain user name notation, i.e. <domain name>\<user name>, i.e.
However, jTDS driver does not recognize the domain included in the user name, i.e. it does not read the <domain> as a domain from the <domain>\<username> but takes entire clause as the username. Hence, the user account read as 'MyDomain\MyUser' would be definitely wrong.
Change the job definition, and instead of having
set it as