This is a Level III feature

This feature provides you with a built-in email client which allows you to send messages and attached PO's to vendors or to send PO's to others within your company. You can compose a personal message to the vendor, or, if desired, you can bring up a default message that you have created.

The internal email client is accessed from the Main Purchase Order Screen.  The following illustration show the two buttons (in  purple) which access it:

To use the built-in email system, you'll need to enter information about your company's email account in Basic Program Set-up: More Information.

Once you've done that, you'll be able to use email functions within the program: