I'm receving junk mail addressed to our domain but not the three email
addresses I have in Outlook. How do I make it stop?!
Filters, to make it stop.
Email goes to the SMTP "RCPT TO:" email address. Always. That is the way
SMTP is designed. The MDA (Mail Delivery Agent), your receiving server, does
not always display this "RCPT TO:" email address; many times it will only
show a "To:" email address. But the "To:" is not a part of the addressing
scheme which directs where the email goes, it is just another part of the
SMTP "DATA" field.