As a project manager working with Merlin I would like to know if there are any quick and easy means of adding emails as attachments onto my project plans?  I am using Apple’s standard Mail.app on a contemporary Mac OS X version.

Sure, just drag and drop emails from Mail directly onto activities of your Merlin project. Merlin will insert them as elements and list them in the according elements area as file elements. Should you want to read the contents of this email message later on, just select it in the elements area, and use the inspector to ‘open’ it again in Mail.app. It’s as simple as that.