When Outbound Private listener is suspended will it cause queues at internal servers?

[bsrinu001]

Hi Team, 

Please clarify, when we suspend the outbound pvt listener on Ironport will the message queues will be occurring on internal network servers like (DLP, Domino & Exchange) end?( as they will relay messages to outbound relay Iron-port)?.

Is relay failure messages (bounce back messages) will be send to internal servers?

Please clarify what will be the general behavior from Ironport to internal servers and vise versa hear?  

[dmccabej]

When the listeners are suspended, the device will appear to Exchange as unreachable and the queues will then build up on the Exchange side. When resumed, Exchange will reach back out to the ESA (based on its retry interval) successfully and anything built up will begin to drain. You can also force a retry delivery on Exchange once the ESA is resumed to make it happen sooner.

One thing to note is that if Exchange (or any other SMTP server trying to reach the ESA) has a lot of built up messages, you're basically opening the flood gates once you resume the listeners and this may cause the ESA workqueue to spike and performance to be reduced until everything has flushed out. 

Thanks!

-Dennis M.