How do I configure email blocking for user access?

How do I configure email blocking for user access? -- Linux general technology-Linux technology and application information. For details, refer to the following section. Xxx has a linux server running FTP and mail services. There are four system users, test01 test02 test03 test04. Requirements:
1. The system user cannot log on locally.
2. test01 and test02 can only use the mail service, but cannot use the ftp service.
3. test03 and test04 can only use ftp to disable the mail service.


My own implementation:
Requirements 1. When creating a user, the shell to be connected is/sbin/nologin [useadd-s/sbin/nologin username].
Requirement 2. You can go to/etc/vsftpd/ftpusers.
For requirement 3, is there any advice from hero?