how to Send a List Email to contacts that are in a relation with certain accounts

I work at a recruitment company and often contacts are responsible for several companies/locations. (Accounts)  

The problem is that when I create a listview in contacts using filters I can only filtert based on the (main) account. The companies that the contact is also in a relationship with are not included when I make the view.  

We first came up with the idea to make a list in reports based on relationships, but then you can't send a list e-mail. (so far i know)  

Does anyone have an idea how I could email everyone in relation to certain accounts?

#Email  #Send Email  #List Views  #Relationships