As you know, recipients can't tell who you included in the BCC field, or even if you used the BCC field at all. But that doesn't mean you can't. To see who you BCC'd in a previous email, just open the Sent mail folder and open the message. You'll see the BCC field preserved for future reference.

Does the recipient know BCC?

Do BCC recipients see each other? No, they do not. Recipients that have been BCC'd will be able to read the email, but they won't be able to see who else received it. Only the sender can see everyone that was BCC'd.

What does BCC look like to recipient?

When you are sending an email to a list of family and friends that don't know each other, for example, put their addresses in the BCC field. The email will look as if it has been specifically sent to them since there won't be anyone listed as CCed.