Update your Antivirus Program

The Outlook message “A program is trying to send an e-mail message on your behalf”, may appear if your Antivirus program is outdated. So ensure that your AV program is updated.

Change the Programmatic Access Security setting in Outlook

To remove the Outlook warning “A program is trying to send e-mail on your behalf”, in case you are actually using a program other than Outlook to send email, turn off the warnings for suspicious activities. in Outlook settings. To do that:

1. In Outlook go to File -> Options. *
2. Select Trust Center on the left and open the Trust Center Settings.

* Note: In Outlook 2007, go to Tools > Trust Center.

At Programmatic Access Security settings select the Never warn me about suspicious activity (not recommended) option and click OK twice to apply the setting. *

* Note: If the Programmatic Access settings are greyed out, then close and re-launch Outlook as Administrator. (Right click on Outlook icon -> Run as Administrator.)