I have downloaded a couple of stationery templates for Apple's Mail application, but I don't know how to add them to the software so I can use them when composing messages. Anyone know how?
These stationery files must follow strict Apple rules, meaning they have to be created in certain ways. If you bought them from Apple they will be fine, however, they should have told you where to place those files.
Having tried unsuccessfully to create my own, I at least learned where to keep them. Here is the path where the files should be placed:
(your) Hard Drive:Library:Application Support:Apple:Mail:Stationery:Apple:Contents:Resources:Photos:Contents:Resources:Air Mail.mailstationery
Air Mail is just one of the Apple stationery packages. Yours might be called Thai Forest.mailstationery.
Hope this helps.