I use Send Mail to send email from FileMaker to Outlook Express and I will get a New Message window from Outlook Express. If I close the window without sending email, a dialog box from FileMaker will appear on screen saying Send Mail has been canceled. Do you wish to continue with this script?

Does anyone know how do I skip this dialog box?

Try putting Allow User Abort [off] at the start of the script.

In the Send Mail script step, make sure "Perform without dialog" is checked. If your email client allows it, the email message will be created and sent without the new message window.