I have a mail server (postfix 2.9.6) up and running with 15-20 users, only for internal usage with one single domain, let's call it xyz.mail.lan
Users are:
user1@xyz.mail.lan
user2@xyz.mail.lan
user3@xyz.mail.lan
…
user5@xyz.mail.lan
No external relay, or incoming mails from internet side is necessary. It works fine right now.
My goal is to limit the users in sending mails to each other.
For example:
- user1 is allowed to send mails only to: user2, user3, user4, user5
- user2 is allowed to send mails only to: user1, user3
- user3 is allowed to send mails only to: user1, user5
- …
- user5 is allowed to send mails only to: user1, user4
I will not have more than 20 users, so I don't mind if my hands has to be dirty with setting up ugly rules for each user.