It's too blunt and confuses the reader. Address and sign your e-mails. This is still a written medium. Follow standard writing guidelines as a professional courtesy. Revisit periodically how you conduct business over e-mail.
Some people are intentionally rude.
But others are inadvertently rude. They have no idea how off-putting they are and never intend offense. If confronted, they'd deny they were rude or be so embarrassed, they'd remember the admonishment and change their ways. Dr. Lynda Falkenstein, author and business development consultant from Portland, Oregon, has the insight to investigate how she may be inadvertently rude. Even if you don't know the answer or don't want totalk to people, return their inquiry somehow.