Oracle System Packages
DBMS_ALERT – DBMS_ALERT supports asynchronous notification of database events.
DBMS_OUTPUT – DBMS_OUTPUT package enables you to send messages from stored procedures, packages, and triggers.
UTL_FILE – UTL_FILE package is used to read and write operating system text files.
UTL_SMTP – UTL_SMTP package is designed for sending e-mails over Simple Mail Transfer Protocol (SMTP).