Hello Team
I am having the doubt about the email flow in hybrid environment with exchange 2010 and exchange online (O365)
. When someone sends an email from on-prem exchange 2016 server . it going over to send connector (Internet) from there normally goes to EOP --> rest of the world
but I can see here - it goes to send connector -->picks any of the source server ---> FDQN ---> EOP
FQDN : specify the FQDN this connector will provide in response to helo or ehlo
is this mandatory to specifiy the FQDN. in My case the FDQN looks like : hyd.ext.com.lifedream.com which IP is public
In my header of the email sent from on-prem to external) showing as
hyd.ext.com.lifedream.com to EOP . Tracer ting the hyd.ext.com.lifedream.com from server it goes to one of source servers.
my doubt is why do we need to mentioned FQDN here during the email routing, Normal t should be blank Only.
is that Public IP belongs to FQDN (hyd.ext.com.lifedream.com) like works like VIP in load Balancer or DNS round robin - - This is my assumption