I'm trying to understand incoming and outgoing NAT rules for OWA and sharepoint. On our firewall there is a NAT rule for OWA incoming and outgoing but only an incoming rules for sharepoint.
OWA Incoming - mail.xxx.com > 192.168.0.1
OWA Outgoing - 192.168.0.1 > mail.xxx.com
SP Incoming - sp.xxx.com > 192.168.0.2
Could one of you experts please explain why we need the OWA Outgoing rule but not the sharepoint outgoing? I'm trying to understand how they work.