SYMPTOM:
Email subscriptions are not delivered successfully via Strategy Distribution Services 9.x and newer and the following entry is seen in the DSSErrors.log file:
2013-09-16 12:55:00.467-03:00 Distribution Service: MSIDeliveryEngine::hDelivery: Email Delivery Failed. Error string from ExecuteMultiProcess 4.3.2 Service not
available, closing transmission channel SMTP Error: 421 Unknown error
CAUSE:
In this specific case, a network firewall was blocking the TCP Port being used by the SMTP service so Strategy Intelligence Server could not establish a connection to the mail server on the referred TCP port.
ACTION:
Make sure that the mail server is available and the TCP port being used by the SMTP service is not blocked.
NOTES:
For additional information on how to interpret SMTP codes, refer to the Strategy technical notes:
