Outlook Not Accessible via House Wifi

My issue is that lately I can't access my office Outlook from home via my home wifi. However when I switch to use my mobile hotspot then Outlook able to connect with the office server. I can access all other sites using m home wife except Oulook (2013). I even have a wifi in the office & it is able to connect to Outlook. So must be the home wifi but at lost how to fix this.