FTP Problems

[Atomic-Design]

I'm making a website for a family that really doesn't know a lot about computers. They gave me the FTP information, but it doesn't work. I got this error message:

530 Must specify domain as part of login.

What does this mean? Do I need to get the correct info, or will this tell me how I can login without asking the family for the "real" info?

[Atomic-Design]

Ok, I figured out it's user@domain.com, but now it says that the user information is incorrect. Blah ... time to get the phone.