Gmail down arrow symbol

You're referring to the arrow symbol in Gmail!

The down arrow symbol in Gmail is typically used to indicate the following:

1. Reply: When you hover over a message, the down arrow symbol appears next to the "Reply" button. Clicking on it will open a new window with the reply message already addressed to the sender.
2. Reply all: When you hover over a message, the down arrow symbol appears next to the "Reply all" button. Clicking on it will open a new window with the reply message addressed to all recipients of the original message.
3. Forward: When you hover over a message, the down arrow symbol appears next to the "Forward" button. Clicking on it will open a new window with the message already copied and ready to be forwarded to someone else.

These symbols are usually displayed as a downward-pointing arrow () or a downward-pointing triangle ().