Forwarding work email to a personal account puts client and company information where it can't be protected.
It can be tempting to forward work email to a personal Gmail or Outlook.com account, to read it on the go or keep a copy. But once it leaves, the information is outside your organization's protections, and it may break your organization's data rules or client agreements.
Already forwarding? Turn the rule off in Outlook and let us know, so we can check nothing sensitive went out. Your organization may block automatic forwarding anyway.