brightmail fake mail
We have a problem about mail security,we saw an issue about our mail clients,
We have a user who name is ayse mehmet.She has an email address which is email@example.com.
However,she is receiving some mails from firstname.lastname@example.org,we wonder that how it is possible that situation?because she says "I didn't send these mails".These mails are coming from outside,not inside.
We wonder that is it a virus?how can we prevent these emails?Can we use brightmail for this problem?