1) On your iPhone/iPad, you need to remove ALL old company accounts. If it asks about deleting contacts, please save them on the device.

  1. Click  the Settings Button on the Home screen.
  2. Select Accounts & Passwords.
  3. Select your Exchange Account.
  4. Scroll down and press the red Delete Account button.

2) Repeat the above for all company Exchange accounts listed.

3) Next you need to add your new email account.

  1. From the device’s main screen, go to Settings > Accounts & Passwords > Add Account > Exchange.
  2. Enter your email address.
  3. Enter your email password.
  4. Select next.
  5. The device may fail stating that your mail server certificate is incorrect, select accept.
  6. Select next.
  7. If you are promoted to enter your username, enter your email address, for mail server enter outlook.office365.com
  8. Enable Contacts, Calendars etc (off by default) as you wish.
  9. Save the settings.