In some cases, such as when someone is on holiday, yes, but first you need to get approval from your line manager (and theirs, if their manager is a different person). Then ask the line manager to submit an IT ticket through this intranet.
If it is a case that someone is leaving, their emails will typically go to their Team Leader but if you have any questions, please first talk to your line manager and then raise it to IT if you need to.