My client has a few users who are having issues connecting to both Yahoo and Gmail SMTP servers in outlook, This started happening within the last few weeks since I installed an ERPro-8 with a Basic Setup Wizard and a few ports porwarded. None of the forwarded ports are SMTP ports, but I did some research for outlook on here and saw that hairpin NAT can be bad. Hairpin NAT is defaulted on in the port forwarding of those ports, so I left it on. Any reason that could be causing problems?
Thanks