Meddling Mother-in-Law

I don’t have a great relationship with my MIL. They just moved out of state. I’m hoping the distance will help strengthen my marriage. My husband flew out to help them unpack. While he was away I saw an email on the computer. His mother said he needs to reconsider moving.... my husband and I want to buy another house here and in the email she is giving him reasons to move there... to be closer to them. She even said since my parents have money that they can fly out whenever... of course after reading this I’m FURIOUS!!!! She has this sick relationship with her son and is interfering in our marriage. How do I tell my husband about this email. I shouldn’t have read the email but it confirms what I’ve been saying to him for 10 plus years. I feel bad because he’s stuck in the middle. Please help!