Email messages are queued after apply smarthost method

After making changes of Smarthost on the Send connector did you restart the Transport service ?
Can you do a telnet from the HUB to the Smarthost and is it allowed to accpet email on port 25 and route external ?

- Rancy

I would agree with Rancy. Check the McAfee gateway. I'm sure you need to tell the gateway that the Exchange server is allowed to relay mail through it. Look through the settings. I'm sure you will find it.

I restarted Exchange transport service after change configuration.
Relay is allowed to smart host IP address.
After change all work fine for about 10 minutes, I mean messages are delivered from Exchange server to McAfee gateway  then messages are queued in the exchange server and they are not delivered anymore to appliance.

When the message gets stuck are you at that moment able to Telnet to the appliance ?
Hope the Appliance is Full version and any events on the HUB server ?

- Rancy

Yes, it is possible run telnet from exchange to appliance.
The applainace currently is filtering inbound email messages normally.
There are any event in the hub transport

So your saying when the issue occurs you can still telnet the Appliance from the server ?
So whats this appliance and does it has some settings or restrictions on size or something ?

There are any event in the hub transport ?? Is there any events on the Exchange HUB server when the issue happens ?

- Rancy

No, there is any event in the hub, there is not restrictions on appliance.
It is possible make telnet