Personal Domain - Email issues - Xfinity Spam

Hi,

I have a domain www.dispatchtruck.com - work domain.

Here is the issue in detail:

1) I am able to receive emails on my laptop, but not able to send any, whether or not I am connected to a hotspot or my xifinity hotspot on the go. But when I connect my personal phone hotspot, the emails go through. So it is an Xfinity spam thing.

2) My dad is not able to receive any emails when connected to xfinity router at home. Hotspots on the go don't give him any problems.

Please help me figure this out. And please at the least show me how to reset the router at my house to clear the spam list on it.

Thanks,

Ali