How to Capture invalid email address?

How can invalid or mal-formed email address (or so called bouncing emails) be captured?

As note: 456378.1 says, after enabling the event WF_MAIL.Disable_Recipient_Ntf_Pref, if a recipient's email address is invalid, an email notification is sent out the SYSADMIN that an email notification could not be sent.
Note:
1. However, this will work only on or after RUP5.
2. Notification preference for SYSADMIN should be MAILHTML or MAIL

to read the complete metalink note, click here