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Forum Discussion

keith_varga_107's avatar
keith_varga_107
Icon for Nimbostratus rankNimbostratus
Sep 24, 2015

Geo-specific SMTP mail routing

Hi F5 Team,   We are faced with a new geo-specific enabled SMTP requirement for one of our applications.   When sending mail into our system, we need the customer to be directed to an appropri...
IheartF5_45022's avatar
IheartF5_45022
Icon for Nacreous rankNacreous
Oct 01, 2015

I assume you have a GTM? Obviously the only source IP that the GTM will see is the IP of the resolving DNS server, rather than the IP of the mail client. Try this (warning totally untested.....) attached to the GTM listener ;-

when DNS_REQUEST {
      if { ([DNS::question type] eq "MX")  &&  ([string tolower [DNS::question name]] eq "varga.com")} {
         DNS::answer clear
         switch [whereis [IP::client_addr] country] {
            "CA" {
                 It's Canada
                set rr [DNS::rr "mxca.varga.com" 1440 IN MX "100 144.100.1.1"]
            }
            "US" {
                 It's the USA
                set rr [DNS::rr "mxus.varga.com" 1440 IN MX "100 150.100.1.1"]
            }
            default
                 It's the world.....
                set rr [DNS::rr "mx.varga.com" 1440 IN MX "100 154.100.1.1"]
            }

         }
          DNS::answer insert $rr
         DNS::header aa 1    
         DNS::return
      }
}
keith_varga_107's avatar
keith_varga_107
Icon for Nimbostratus rankNimbostratus
Oct 01, 2015
thanks much iheart. We were just quoted $30,000 for two GTM's from F5 sales. However, we don't have that cash laying around, so we're going to build a linux server with bind, and use a free plugin to get it done. Thanks Keith