[postfix-es] No me deja enviar correos a este destinatario

[Rosario Muñoz]

Me devuelve el correo y no sé cual es el motivo pq creo que lo tengo 
bien configurado.

El error es el siguiente:

This is the Postfix program at host servidor2.itsmo94.com.

I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

			The Postfix program

<lmurillo en chguadalquivir.es>: host www.chguadalquivir.es[212.170.226.193] said:
    554 5.7.1 This message has been blocked because the HELO/EHLO domain is
    invalid. (in reply to RCPT TO command)


¿Qué ocurre?

Gracias. Un saludo.