How to block e-mail from certain group to a specific e-mail address
 

Is there a way of allowing only certain domain to send e-mails to certain specific e-mail address.

I am using Sendmail, and I have an alias which translate to certain members of staff within my organization. I don't expect e-mails from outside our domain to be sent to this alias e-mail address. Is there a way of achieving this?

actually answered incorrectly,.,,misread the post...