What are blind carbon copy and send separately

Blind Carbon Copy: Recipients can see the mailbox addresses in the recipient and carbon copy fields. The addresses of blind carbon copy recipients are not visible.

Send Separately: Each recipient in the field receives a unique copy of the email. The email appears as if it was sent only to that recipient.

In Send Separately mode, you cannot add carbon copy (CC) recipients. A separate email is generated for each recipient, so the CC function is unavailable in this mode. To add CC recipients, cancel Send Separately mode first.