Mail: Contact Pictures

[MBPro825]

So, I like how mail puts pictures besides the mail conversation.

However, there are often times people from the same group or organization email me from various addresses...example "bobsmith@mymail.edu, joesender@mymail.edu, etc."

How do I add a rule to mail that allows me to display the same contact picture (possibly from address book) to all addresses ending in something like "@mymail.edu"

 

[matbook101]

You just add that picture to all of those contacts.

 

[MBPro825]

You just add that picture to all of those contacts.

I was hoping to add all the people to the same contact labeled "Organization", because I don't know personally know a lot of the people who send me notices and such. Is there a way to just add all these email addresses to one contact as they come?