The University Information Service is now providing e-mail accounts via Exchange Online as well as the existing Hermes e-mail service. Students can decide which service they prefer to use. There is information on the UIS website regarding transferring your mail account from Hermes to Exchange Online.
We would strongly suggest only migrating from your existing Hermes account if you are comfortable with the features available in Exchange Online. There is the possibility of reversing the migration process but this can only be done by contacting the UIS directly.