Changing External FTP Access

Right now to access our FTP site externally we are typing ftp://ipaddress . Can we change this to ftp://domain.com ?? For instance, our email domains are @abcinc.com. Can we have our clients access the FTP site by typing ftp://abcinc.com?

Accessing the ftp site internally is down in one of two ways: ftp://domain.local or ftp://privateIPaddress .

Thanks!