User blocked Incoming and outgoing disable

User blocked Incoming and outgoing disable

User : gani.badar@ams-trust.com.my
Details :Mail Incoming blocked. Reason :MailBox Size Exceeds Limit [MailBox Size=5,123]. Mail Fetch has also been disabled for any active POP accounts.

I had clear some of the mails. Please help me to unblock.

Thank you very much.