How do I send mails to undisclosed recipients via Gmail?
1 Click on Compose in Gmail to start a new message.
2 In the To field, type Undisclosed recipients < followed by your Gmail address and a closing >. For example, if your Gmail address is email@example.com, you’d type undisclosed recipients < firstname.lastname@example.org>.
3 Click Bcc.
4 Type the email addresses of all intended recipients in the Bcc field. Separate the names by commas.
5 Now enter the message and its subject.
6 Add any formatting using the toolbar at the bottom of the compose screen.
7 Click Send.