Relay fails - exchange server

I am trying to set up mail to go to my exchange server at the office. However I get a relay issue - it looks like the mail still goes to dreamhost. I am at home (comcast) and can send to every e-mail address accept those on my exchange server which is connected via a different ISP. I don’t think the issue is authentication but a bad record on my Dreamhost account or something needs to change on my SBS server.

I created an mx record -

mail MX then for value I put 10(SPACE)

When I try to send to any e-mail address I get the following -
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

SMTP error from remote mailer after RCPT

host []: 554

Relay access denied

Which server is bouncing the mail? DH or your own mail server? Posting the entire bounce message would be more helpful. Also, run the following from a command line and post the output:

nslookup -q=mx <domain> Then try the same using a different DNS server, for example (assuming you’re not already using Earthlink):

nslookup -q=mx <domain> Using your actual domain name would be helpful as well.

If you want useful replies, ask smart questions.

Thanks - The error went away after a few hours.