Keep email addresses anonymous from other recipients
Use the Bcc field to send an email to one or more recipients without disclosing the email address to other recipients. The Bcc field works like the To and Cc fields in Microsoft Outlook. Using Bcc depends on specific circumstances, but it is useful when sending email to unknown recipients in Outlook.
The instructions in this article apply to Outlook for Office 365, Outlook 2019, Outlook 2016, Outlook 2013, and Outlook 2010.
Add BCC recipients in Outlook
Recipients added to the Bcc field will not be visible to other recipients of the message, even those who are also in the Bcc list.
Open a new email message or reply to or forward the message.
In a new post, go to the tab parameters: † In a reply or forwarded message, select the tab Message †
In a group Show fields select Hidden copy †
in field Hidden copy enter the recipients whose addresses you want to hide from other recipients.
in field To who enter at least one email address. This can be your email address or another email address. The address in the “To” field is visible to every recipient, even the hidden ones.
To quickly enter an email address in the Bcc field, click To who to open the dialog Choice of names highlight name, select SC strong. > then press Okay when you add all recipients.