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How to forward SMTP traffic to external SMTP relay?


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Hello everyone, 


I have been requested to forward all internal smtp traffic to external smtp server 

so basically, netscaler should be the middle man as an smtp relay,

the customer want want to, send from internal systems like notifications etc using smtp, to the netscaler IP/vserver etc, and 

then netscaler send everything to an external smtp server.


not sure how to accomplish this request

i know how to LB smtp servers , so internal smtp traffic hit the LB and behind the LB there will be the smtp servers, to process the request.

but with this new customer requirement, I'm a little bit confuse now on how to make this new requested setup.. again 

they want to forward smtp traffic to outside of their network, to an smtp relay in cloud, they have the cloud smtp hostname and port 


any idea? 



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SO you've already got a setup with SMTP LB vServers and sending the SMTP traffic to the backend?


What is configured on the backend? to route the traffic back, are you using USIP? Direct Server Return? ADC set as Gateway on backend? Does customer need to replace the backend servers with SMTP in the cloud?


Some great info here: https://www.mycugc.org/blogs/braxton-koppelman1/2020/07/07/securing-exchange-smtp-relay-hosts-with-citrix-adc


There are a number of different ways to set up SMTP, and secure it, using responders, pattern sets etc

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