The security dialogs that pop up when an application tries to access certain
Outlook properties and methods are designed to inhibit the spread of viruses
via Outlook; see http://www.slipstick.com/outlook/esecup.htm#autosec. They
cannot be simply turned on or off with a user option or registry setting.

Standalone users can use a free tool called Express ClickYes
(http://www.express-soft.com/mailmate/clickyes.html) to click the security
dialog buttons automatically. Beware that this means if a virus tries to
send mail using Outlook or gain access to your address book, it will
succeed.

If it's a VBA application you wrote yourself, you have these options for
modifying your program to avoid the security prompts (roughly in order of
preference):

   -- Use Redemption (http://www.dimastr.com/redemption/), a third-party
COM library that wraps around Extended MAPI but parallels the Outlook Object
Model, providing many methods that the Outlook model does not support

   -- Use SendKeys to "click" the buttons on the security dialogs that your
application may trigger. See
http://www.slipstick.com/outlook/esecup.htm#autosec for a link to sample
code.

   -- Program the free Express ClickYes
(http://www.express-soft.com/mailmate/clickyes.html) tool to start suspended
and turn it on only when your program needs to have the buttons clicked
automatically.