This is for workspaces with the newer Mail.
What it means
An admin can choose a lowest rank for Mail (Settings > Mail > Who can use Mail). Only members of that rank or above get Mail. Everyone else sees "Mail needs a higher rank: why you see it and what an admin can do" instead of an inbox.
What happens to you if you are below the line
You cannot send email, and you do not get Discord messages for new email.
Email sent to you still arrives, so nothing is lost if the rule changes. It is waiting when you are promoted or the rule changes.
Someone with no rank on record counts as below the line.
What does not change
Workspace admins always have Mail, so nobody can lock themselves out.
The rule is enforced everywhere: Mail pages, sending (including scheduled email) and Discord messages. Hiding the menu item is just a courtesy.
If you think this is a mistake
Ask an admin which rank is set and what yours is. If you were just promoted in Roblox, ask an admin to resync the group so Rosterr sees your new rank.
For admins
Open Settings > Mail > Who can use Mail and pick the lowest rank, or clear it. The change takes effect straight away.
Related articles
Turn on Mail for your workspace (admins): short name, sender name, signature and rules