Can't send, error 0x800CCC6F - Oulook 365

New laptop, set up Outlook, worked fine for both sending and receiving. Literally changed nothing on machine and outgoing mail started failing.  Outgoing error message from Outlook referenced above and says to contact provider, WebMail works.  Called support to verify server settings.  Outlook says outgoing server settings "something went wrong" setup failed when making any changes to outgoing server settings, retry.  Cox says, WebMail works, not our issue. So what changed?  Nothing on my machine changed except the outgoing mail failure.  Cox?  Anyone?