When SDC tries to send an email through an SMTP server that is configured as an anonymous relay (no username or password required), this error appears:
EmailException: javax.mail.AuthenticationFailedException: No authentication mechansims supported by both server and client.
Solution:
Try setting
mail.smtp.ehlo=false in the sdc.properties file.
This disables the EHLO command, and might be needed for servers that are configured to not expect a username/password.
