I need TOP expert of MS Office who knows how to handle errors

I need TOP expert of MS Office who knows how to handle errors when doing mail merge. Only one who is top level of office who knows the fixes of office programs communicates with each other can solve that. I want to pay only if solved by defined time frame to solve. The current state is that Word merge at Office 2007+ Win 10 reads from Excel but doesn’t send the E mails with Outlook. Till yesterday it works just fine. I didn’t do anything regarding office settings at that time.