Delay of email from Hub Transport to mailbox.

[Jaycee]

I'm expriencing around 10 minute delays of emails from the Hub Transport
servers to the mailboxes. I can see in the MessageTracking logs on the hub
server that the message is recieved on time but I don't see it sent off
until about ~10 minutes later.

Message flow:
Mail Security gateways -> Exchange 2007 Hub Servers -> Mailboxes on Exchange
2003.

Log files:
Receive from gateways:
2009-01-16T20:34:53.203Z,12.12.12.176,,12.12.12.225,HUB02,08CB291E046C5569;2009-01-16T20:34:52.953Z;0,HUB02\Inbound
SMTP relay
(WNLB),SMTP,RECEIVE,755326,<200901162034...@mx01.domain.com>,jsm...@domain.com,,1540,1,,,test123,jsm...@domain.com,jsm...@domain.com,00A:
Send to Exchange 2003 mailbox:
2009-01-16T20:46:05.580Z,12.12.12.213,HUB02,12.12.12.3,EVS11.domain.com,08CB291E046C5667,Intra-Organization
SMTP Send
Connector,SMTP,SEND,755326,<200901162034...@mx01.domain.com>,jsm...@domain.com,250
2.1.5 jsm...@domain.com
,1728,1,,,test123,jsm...@domain.com,jsm...@domain.com,2009-01-16T20:34:52.969Z

Also when I run the get-queue cmdlet I can see a message count and the last
error states:
451 4.4.0 Primary target IP address responded with: "421 4.4.2 Connection
Dropped." Attempted failover to alternate host, but that did not succeed.
Either there are no alternate hosts, or delivery failed to all alternate
hosts.
The status is also set to "Retry"
...I'm not sure it this info from get-queue is in regards to sending to the
mailbox server or not.

Also, in the application log I see this error. Not sure it it pertains to
the problem or not.
Log Name: Application
Source: MSExchangeTransport
Date: 1/16/2009 3:51:48 PM
Event ID: 8010
Task Category: RemoteDelivery
Level: Error
Computer: HUB02.domain.com
Description:
A message with the internal message ID 540355 was rejected by the remote
server. This message will be deferred and retried because it was marked for
retry if rejected. Other messages may also have encountered this error.

Any ideas???

Thanks,

Jaycee