Dirty flag
When this option is on, a dirty flag will appear on the left-hand edge
of the status line to let you know
when you haven't sent a message yet. Whenever you alter the text of the
message, the dirty flag will appear; whenever you send or clear the
message, the dirty flag will disappear. This is useful to keep
track of whether or not you've sent a message.
Here's the normal status
line.
Here's the status line
when the message is dirty.
Back to the Sender Options dialog page.