As a service provider, I never want to say, “Can you send that again? I don’t know how to open that file type.” Now, as a caveat, if a client sends a low-res jpg and I want a vector file, I’ll ask them to keep digging until they find an editable file I can use and manipulate. However, if they send me a Publisher file and I don’t use Microsoft Publisher, I will not ask them to send it again.
Instead, I use one of the MANY online converters. For instance, just today, I used a Pub to PDF (https://www.zamzar.com/convert/pub-to-pdf/) converter to view the details of a Publisher file a client emailed over.