geoffreye here,
i have outlook 2007 w/ gmail and cox set-up in "account setting" and "internet e mail settings" according to gmail and cox numbers and checked and dots and drop downs.
in outlook 2007 i can send on gmail but not on cox, i can receive on gmail and on cox.
running on win 8.1 pro
the next thing i want to say will only get me in trouble and severs no purpose as i don't know how cox handles the smtp on the servers.
this from gmail account "test account settings"
"This is an e-mail message sent automatically by Microsoft Office Outlook while testing the settings for your account."
so...for now i am running outlook 2007 and sending on gmail account. and the cox account is just there.