Unable to send email through outgoing SMTP server when not on Cox network

Hello,

I have a laptop with Win10 and Outlook 2010.  The settings I use are for SSL

Incoming POP3 server using SSL on port 995

Outgoing SMTP server using SSL on port 465

Everything works fine when I am at home using Cox Internet service.  But, when I go mobile with my laptop, I can get email through the incoming server but get an authorization error when I attempt to send mail .

I read through Cox's email instructions and do not see anything about using a different port or other configuration settings for the outgoing server. 

Would like to hear if anyone has sorted this out.

Thanks,

Steve