Consequently, it is "Reply" you click and Command-R you press; like just now, as you've finished composing an email addressed to one — intended for all.
Do you have to start over; copy and paste the text perhaps? You don't. Mac OS X Mail expects you to use "Reply" every time and can turn what you've already concocted into a reply to all in no time.
Pick Reply or Reply All After You've Started Replying in Mac OS X Mail
To switch between replying to just the sender and replying to all recipients of the original message in addition fast in Mac OS X Mail:
- While composing a reply (even after you have started typing your message):
- Click Reply All to include additional recipients from the original email as Cc: recipients of your reply.
- Click Reply to remove addition recipients and have your reply addressed to the original sender alone.
You can also press Command-R to switch to replying to just the sender and Command-Shift-R for replying all.

