To verify emails that have gone to quarantine, go to your Quarantine page via the following link: https://security.microsoft.com/quarantine
When you have accessed this website and logged in with your University of Leeds credentials you will be able to see a list of any quarantined emails. You have 14 days to take action on these emails e.g. block sender or release the email if it was wrongfully quarantined, so it appears within your mailbox. If any emails within the quarantine have not been actioned within the 14 day limit then Microsoft will automatically delete them.
For more information regarding quarantine please visit the Microsoft article linked below and scroll down to ‘Take action on quarantined email’ & ‘Release quarantined email’: