Blocked IP?

I have the exact same problem with a Windows based machine using Outlook 360.  Same errors except it is a different IP address listed.  Mine says it is 8.40.179.163 which is not an IP I am aware of.  I do not have an IT department as I am at a residence.  I am using a different ISP other than Cox to access the internet but I am paying Cox 9.99 a month to keep my email address and data.  This problem started about the last week in April.  I checked with my ISP, Vyve Broadband, and they are telling me that Cox is failing the DNS from them.  Please resolve this issue and allow.