Final answer:
To send an email to multiple recipients without them knowing who else received it, use the BCC field of your email account.
Step-by-step explanation:
To send an email to 3 different recipients without anyone of them knowing such email has been sent to others, you make use of the BCC (Blind Carbon Copy) field of your email account. When you put recipients' email addresses in the BCC field, they will receive the email without knowing who else received it. This is useful for maintaining recipients' privacy and preventing them from seeing each other's email addresses.
Learn more about Using the BCC field to send emails secretly