This article explains how to send an email to unknown recipients. Instructions apply to all email services.

Create a new message in your email client.

Type Undisclosed Recipients in the To: field, followed by your email address in < >. For example, type Undisclosed Recipients.

In the Bcc: field, type all of the email addresses you want the message to be sent to, separated by commas. If these recipients are already contacts, it should be fairly easy to type their names or addresses and the program will fill in those items automatically.