Jim F wrote:

I am using a public "hotspot" WiFi connection. I've another computer
using the same WiFi hotspot and its SMTP/POP works fine with Outlook.
So I'm guessing it's not the ISP. Even though I've disabled the
firewall, it acts like the mail ports are being blocked. Is it
possible there's some "hidden" firewall running? I've not been able
to find one in add/remove programs...

Then on one you may be authenticating to the outgoing server and on the
other you're not.
--
Brian Tillman