[feature] Mail system.

[sakurawald]

Is there an existing request for feature?

• I have searched the existing issues

What feature would you like?

One more thing I will miss in CMI plugin is the mail system. For server admins, the server gets updates, and the players should know what are the changes.

For this use-case, a mail system will be nice.

There are 2 kinds of users:

1. For admin player, they will need to send a mail to all players in the server, after the server gets new content update.
2. For normal player, they will need to send a mail to another offline player as a PM.

For this system, I hope there are some features:1

1. Compared to /send-broadcast, the mail is able to sent to offline players.
2. For admin player, they can send a mail to all players in the server.
3. The text in a mail can be paged.
4. For admin player, they can send a mail in message or book.
5. For normal player, they can list mails, delete mails and send mails. (With luckperms permission)

Anything else?

This is a draft, I didn't know what is missed.