Need help to design the relationship in between two nodes

My requirement is to send the email to the users who is registered .I want to keep the separate process of sending the email message like message body subject etc.

Keeping the data of user in one node and message is another node.

Will send the message later on by the scheduler to the user.

How should we design the relationship in between user and message?.

Hello, welcome to the community. I'm not exactly sure what you're trying to accomplish but it sounds like something kind of like this is what you're after:

This would allow you to keep track of which users are sending what to who, as well as preserve the message text and a scheduled send time. If that's useful to you I made that diagram with:
Arrow Tool which is a great tool.