[postfix-es] problema en entrega de correo

[luis en ida.cu]

Hola a todos

Tengo problemas al entregar un correo a determinada dirección esto es 
lo que me da:

----------------------------------------------------------------------------------
This is the mail system at host lsm.ida.cu.

I'm sorry to have to inform you that your message could not
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 mail system

<oldarys en aseguramiento.ohc.cu>: host relay-out.ohc.cu[200.55.138.44] 
said: 550
     5.7.1 <lsm.ida.cu>: Helo command rejected: Host not found (in reply 
to RCPT
     TO command)

Reporting-MTA: dns; lsm.ida.cu
X-Postfix-Queue-ID: EA7EB2B404EF
X-Postfix-Sender: rfc822; luis en ida.cu
Arrival-Date: Tue, 28 Oct 2014 16:31:07 -0400 (CDT)

Final-Recipient: rfc822; oldarys en aseguramiento.ohc.cu
Original-Recipient: rfc822;oldarys en aseguramiento.ohc.cu
Action: failed
Status: 5.7.1
Remote-MTA: dns; relay-out.ohc.cu
Diagnostic-Code: smtp; 550 5.7.1 <lsm.ida.cu>: Helo command rejected: 
Host not
     found
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Alguna idea esto solo me sucede con 2 o 3 direcciones de correo a los 
cuales se les envía y no reciben correo demi servidor

agradezco toda ayuda