We often email quotes, Purchase Orders, and Payment notifications directly from Sage 50.  The Outlook pop-up will show (after a delay) and then show again (after another delay) and then send the email (after a delay).

These measures are important to prevent an unprotected computer being turned into an Outlook junk-mailing zombie.  

But if, like me, you have good antivirus / anti-malware and a good firewall, and have clicked on the message a few thousand times and it's never been any program but Sage 50 that was sending Email, you may want to disable this security feature.   I've tested this work-around and it found it to work well:

http://noexcusenow.blogspot.in/2010/04/disabling-programmatic-access-security.html

** Warning, this requires modifying the Windows Registry directly, which is risky **.   Make these changes only if you follow good backup and security practices, and even then, only if you are qualified to do them.