After piecing together how to do this, I got the Caregroup/BIDMC emails working on my iOS devices.  FYI: It will require you to have at least a 4-digit password. It also may require you to change your 4-digit password.

Step 1: Go to Settings and click “Mail, Contacts, Calendars”

Step 2: Click “Add Account…”

Step 3: Select “Microsoft Exchange”

Step 4: Enter info as shown. Hit Done.  NOTE:  Your username is the first part of your email (before the @ sign).

Step 5:  The first attempt at verification will fail, and a new section will appear called “Server”.  Put in mail.caregroup.org

Step 6:  Hit submit.  You should be all set.