error 550 5.7.1 Unable to relay for

Exchange server had a drive go bad after getting the new drive going we have been having nothing but problems sending mail not receiving ( server was down for a week) but nobody has addmitted to making any changes. I am new to exchange and don't have a clue where to look. All mail is sitting in the smtp queue. any Ideas? Thanks in advance.

below are some logs after running mxtoolbox

mx:*******.com mx

Pref Hostname IP Address TTL
10 sm07.internetmailserver.net 64.79.170.137 60 min SMTP Test Blacklist Check
dns lookup ns lookup mx lookup whois lookup

Reported by ns2.discountasp.net on Thursday, March 10, 2011 at 3:22:33 PM (GMT-6)


a:*******.com a

Type Domain Name IP Address TTL
A *******.com 000.000.000.000 60 min
dns lookup ns lookup mx lookup whois lookup

Reported by ns2.discountasp.net on Thursday, March 10, 2011 at 3:22:23 PM (GMT-6)


smtp:*******.com smtp
220 web708.discountasp.net Microsoft ESMTP MAIL Service, Version: 7.0.6002.18222 ready at Thu, 10 Mar 2011 13:21:46 -0800
OK - 96.31.33.28 resolves to web708.discountasp.net
OK - Reverse DNS matches SMTP Banner
0 seconds - Good on Connection time
Not an open relay.
0.250 seconds - Good on Transaction time

Session Transcript:
HELO please-read-policy.mxtoolbox.com
250 web708.discountasp.net Hello [64.20.227.133] [31 ms]
MAIL FROM: <[email protected]>
250 2.1.0 [email protected] OK [47 ms]
RCPT TO: <[email protected]>
550 5.7.1 Unable to relay for [email protected] [47 ms]

dns lookup ns lookup mx lookup whois lookup

Reported by mxtoolbox.com on Thursday, March 10, 2011 at 3:21:40 PM (GMT-6) (History)