sending and receiving emails to certain contacts
I have an email account here in the office that for some reason has stop sending and receiving emails to certain contacts. Also they have stopped receiving junk email. I have double and triple checked all the settings I even lowered the level for junk emails with no luck. They can send an email and sometimes the person gets it and sometimes not. Also if they receive the email and then reply the person is not receiving that email. Any help I am at a loss.