Incoming mail- linking to additional contacts

Incoming mail- linking to additional contacts

I would like to reassign or add addtional contacts to link to incoming mail.    We use MYFAX for incoming faxes and this shows the sender as MYFAX.  I have created a contact MYFAX  which has all of the documents associated with it.  What I would like to be able to do is either redirect to the proper account or add the proper account to the email. 
 
I used Goldmine several years ago and they had this feature. It was quite helpful.