Alternatively, you can select the tag in the publication edit area. When the tag is selected, the blue line of the tag frame changes to black dotted lines. When the tag name gets highlighted, the Properties pane displays.
Set an Action in the Properties pane.
Set the Action as Link.
Choose the Link type as an External.
Select Mailto://. A text box with Mailto:// displays.
Enter the email address.
Choose the Icon type as an External icon.
Select the Icon position from the drop down list of items: Top left, Top right, Top center, Center left, Center right, Center center, and Bottom left.
Select an Active area either as Full or icon only.