You can use Safeguard Send for this from Sperry Software;
http://addins.howto-outlook.com/sperry_safeguard
If you decide to order use BH93RF24 to get a discount.

--
Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more

http://www.msoutlook.info/
Real World Questions, Real World Answers

-----

"Simon Minder" wrote in message
...
Dear all,

Let's assume I have 15 contacts in my contact list in Outlook. 5 contacts
are clients and I would like to get an alert (e.g. a message before I send
/
background color of the message changes, when I add one of these five
contacts), before I send the e-mail.

The alert would allow me to review the message once again before the
message
get sent out.

Do you know any Add-in that would support this functionality or could I
solve this with VBA?

Best wishes,

Simon Minder