How to Edit Received Email in Place with Mac OS X Mail

Why not turn on the light in the hallway instead of in the courtyard, I thought.
Why not get rid of the bicycle's lighting also and prepare the lock?
In the middle of the hallway, deep in thought, I opened the lock — and secured it tight around rear tire and frame.
That the bike would not move surprised me. I hope nobody saw me schlepp a locked bike zig-zagging across a dark courtyard.
Now, emails you receive are usually locked and severed. In Mac OS X Mail, you can schlepp messages across the Desktop, though, and make desired changes — to the Subject, for example:
›› Want to change the subject of or maybe fix a link in an email you have received? Here's how to edit messages in place in Mac OS X Mail.