Once you finally get your Outlook automation up and running you will notice that your users receive a security prompt each time your database attempts to send an automated e-mail. Obviously, as a programmer this is not the ideal situation and there are a couple of options available to you.
Outlook Redemption
This solution is often mentioned in numerous Forums. For more information refer to http://www.dimastr.com/redemption/home.htm
vbMAPI
Another alternative is vbMAPI which you can review at https://www.everythingaccess.com/vbmapi.asp. I have no personal experience with this product, but it has been highly recommended to me by multiple very reliable source.
CDO
Another commonly refered to solution found in numerous Discussion Forums. The following website provides several example of programming with CDO.
http://www.devhut.net/2014/11/29/vba-cdo-mail/
Thrid Party Emailing Utilities
In my past life, when I was working for a multinational company, the work around that I implemented was to use BLAT to send the emails. I used VBA to produce a text file based on this information from within the database and it in turn was utilized by BLAT to send the email. It worked seemlessly! Best of all it is free.
VBScript?
Someone once mentioned that they could send emails using VBScripts without getting the security prompt. This said, I have never validated this yet.
Third Party Application to Automate the Confirmation
There are several little utilities available online that you can install on your clients computers that will simply automatically Click the Yes button to authorize that the email be sent. One of these programs is ClickYes. This however, bypasses security completely and could be considered a serious security issue.