Bad sequence of commands

If you run CSSMTP with Transport Layer Security (TLS) and you are receiving reply code 503 bad sequence of commands after a successful TLS negotiation, it is possible that the mail server requires an EHLO SMTP command following the TLS negotiation. Set the TLSEhlo option to Yes in the CSSMTP configuration file if an EHLO SMTP command is required following the TLS negotiation.