Load Balance SMTP for Exchange 2007 relay

Thanks for the background info. If the SMTP server being load balanced could read the custom header, it could trust what LTM inserts for the client IP LTM receives. As with HTTP, you'd probably want LTM to remove any pre-existing instances of that header though to ensure malicious clients couldn't inject their own value. However, as Jason pointed out, all of this is a nice academic discussion if the server can't do anything with the header value.

 

 

Aaron