There are many kinds of group software, so I won't mention them here. Take my own TOM VIP mailbox for example.
E-mail mass sending methods include: cc mass sending, mass sending and secret sending, or adding multiple recipients directly.
Cc group cc group cc group cc
After filling in the recipient, fill in the account number of the person to be sent to the cc, and you can complete the cc mass sending.
Group secret delivery group secret delivery
Mass bcc is similar to mass bcc. In addition to filling in the recipient at the bcc, you should also fill in the email account you want to send, so that both the recipient and bcc can receive your email.
Add multiple recipients
Multi-recipient group sending
At the recipient's place, fill in the recipient's account number, and press the "Enter" key after each account number is entered, so that multiple recipients can be entered or sent in groups.
Supplement:
A mass mailing list is similar to a multi-recipient mass mailing, in which multiple recipient accounts are entered at the recipients.
The difference is that the recipients of the mass mailing list will not feel mass mailing when they see that the email is sent to themselves separately.