disable ndr on sendmail

Disable Ndr On Sendmail

If you operate a private domain, have your hosting or mail service disable catchall addresses unless you have a good reason to use them.
A Lock-In is similar to a mousetrap in that lock-in code disables your browser's Back Button and prevents you from leaving the web site.
Tip: Disable Active-X and Javascript except when visiting trusted sites, and always disable them afterwards.
Many systems disable address verification completely to prevent spammers from harvesting email addresses.