Using SNDDST for internal email

Hope someone can shed some light on this for me.

 

I have configured our iSeries (V5R1) to allow me to use the SNDDST command.

I am able to send email to outside email addresses such as
midrange-l@xxxxxxxxxxxx

I am not able to send emails to any email addresses with our own corporate
email address.

 

Our AS400 user Id's do not match our corporate email address names.

When I execute the SNDDST our mail server never gets the email

We are using iMail for our Mail Server

 

I can use TELNET from the 400 and it sends the email without any errors
messages

Telnet rmtsys(exchange server full qualified domain name) port(25)
HELO domain.com
mail from: email_address.com
rcpt to: exchange.email@address
data
subject:test from our as400
This is a test message
.
quit

 

I read somewhere that our AS400 may be thinking it is local mail and trying
to distribute to a local mail user

But I do not know exactly what that means? 

What can I do to stop this if it is my problem?

If it is not my problem where should I look and what should I be looking
for?

 

Thanks

 

Over my head, Allen