In the subject line field [1], enter a subject line for your message.
If you are sending your message to multiple users, but you do not want each user to see who else was included in the message, click the Send an individual message to each recipient checkbox [2]. If your message includes over 100 recipients (including you as the sender), this checkbox will be selected by default.
In the message field [3], type your message. All content is sent in plain text. Note that if you include a URL in your message, the URL will automatically become a clickable link after you send the message.
If you want to include an attachment or media file, click the attachment or media file icons [4].
When you are finished, click the Send button [5].