Sender Policy Framework (SPF) is has been designed to reduce or stop forged email
from being sent.
The domain the sender says that it is from gets checked by
the Sender Policy Framework(SPF) and checks if the sender is allowed (according to the DNS entry) to send email from
that domain. In this case, the offender tries to send mail from a fake
address, then the message will be rejected.
To accomplish this you will need to add a text record to the DNS to define the mail servers allowed to send on behalf of the domain.
An excellent resource for learning more about SPF records on how to create them is OpenSPF.org.