hi guys, would need some guide/advice on the above if it's archive able without setting out 2 exchange environment. thanks guys appreciate it.

There are testing tools available for download: http://technet.microsoft.com/en-us/exchange/bb330849.aspx Exchange Load Generator Exchange Server Stress and Performance Exchange Server Jetstress

Hi thx for the reply, but what actually we really wanted to test is on the flow to external and internal domain in the lab hence those tools are not applicable. Thank you.

Hi, Well why no just send a mail to and from manually, you don't really need tools just to test it. /MartinExchange is a passion not just a collaboration software.

we are actually trying to simulate the external auto reply in lab, hence need some guide if is possible to setup external traffic in lab, our lab environment is isolated from internet. Thank you.

Well hmm, one way would be to have an extra exchange org or other mail server that would connect to the external receive connector. This can be done by create MX records on the extra server. It is some work to do, but I don't know of any other way. For a semi simple solution you could install one virtual server whitch could be a DC and Exchange, then create MX records in the DNS server and point them to the lab exchange server. It should work, but i never tried it since my lab has a demo domain and is connected to the internet. /MartinExchange is a passion not just a collaboration software.

Hi zomwalk891, Mracket, gave some good suggestion. Per your description, you want to test the external auto reply, so you want to check the auto reply message, that mean, you must built a email system and create a mailbox to simulate the external mailbox. In fact, just need the two email system at different network subnet, and let the the mail flow use the external receive connector, and then it would simulate the scenario that you want. Regards! Gavin