For staff, College email and accounts will cease functioning on the day your contract finishes. If you are a student, you will have access to an alumni account.
The college does allow continued access to your account after you finish, for writing-up papers and continuing to collaborate on research with your supervisor. Your supervisor will need to ask for you to be given Visiting or Honorary research status in the college.
Please note even if your account is extended, your access to specific facilities (e.g. the VPN, using licensed software) is dealt with on a case-by-case basis.