The answer is no, you are not legally obligated, but yes, your job is in jeopardy if you do not. You are not legally obligated because the most that could be done is to fire you--you can't be sued or otherwise penalized--but assuming you are an employee at will (no employment contract), you may be terminated if you refuse to cooperate with the company.Several things to bear in mind:1) The company doesn't need your permission to access any emails to/from a company email address, or sent over/through its server or network--it has the right to access its own systems and computer equipment.2) Even if you don't agree to provide access, one side or the other (company or former employee) could attempt to subpoena records and testimony from you if they believe it is relevant to the case. If it is not relevant, and/or contains certain kinds of especially private or privileged communications, you could likely resist turning it over if subpoenaed, but there is a reasonable chance you could be compelled to provide at least some of your communications or phone records involving this person.