Question: Can't edit draft email created from stationery
I have several draft emails that I created from Mail's stationery. Most of them act fine, but there is one that I cannot edit. I have tried moving it around in my Mail folders and deleting and recreating it, all to no avail.
This is a new computer and I imported all my mail, apps and settings when setting up the Mac. This is the first time I have tried to edit this particular email on this computer. I edited it with no problem on my previous Mac mini.
Does anyone have any idea how to solve this problem? Thanks in advance for any help you can provide.
MacBook Pro with Retina display, macOS High Sierra (10.13.3)