Friends of mine just iPhone 4 phones Husband and wife. He is getting her emails.How can you take care of this problem?

Go to: http://appleid.apple.com. Make a new ID.

Enter it on your iPhone: Settings > Messages > Send & Receive.

Sounds like both phones are using the same Apple ID. Many people do this but it is best to have every individual have their own Apple ID, email address and phone number. The phone numbers are already different. So you need to sign out of the Apple ID on the husbands phone, create a new Apple ID for that phone and sign in.

You can do this in the Settings app.

settings> iTunes and App Store > Apple ID