FDPSTP failed due to ORA-20001

[admin]

Cause: FDPSTP failed due to ORA-20001: You have exceeded the maximum number of email messages per workspace. Please contact your administrator.
ORA-06512: at "APEX_180200.WWV_FLOW_MAIL", line 612
ORA-06512: at "APEX_180200.W04-DEC-2019 13:39:16

By default, the limit is 1000 messages per day and you can change,

Login as Internal workspace > Click Manage Instance > Instance Settings > Maximum Emails per Workspace

Make it higher than 1000