Which setting(s) would prevent Discourse from emailing an old user?

[watchmanmonitor (Allen Hancock)]

Continuing the discussion from Disable user account and what’s the difference between Suspended and Blocke users?

Which of these options would also prevent them from ever getting an email from something they are Watching or via Mailing list mode?

[jomaxro (Joshua Rosenfeld)]

Blocked will stop mailing list mode, suspended will prevent all emails (except for staff PMs).

See

Description of various user states in Discourse (Admin / Moderator / Staff / Developer / Other)

Discourse has many built in user states, the following describes the meaning of each state and basic storage implementation: Admin Admin users are the superusers in the system, they can: Impersonate non admins Change site settings Create groups Amend site customizations Perform all the actions moderators can perform Read any personal message Create, delete and modify categories Ignore category permissions to view private categories Storage: The boolean field admin in the users table flags …

[fefrei (Felix Freiberger)]

Deactivating will also prevent mails, until the account is active again.
(Therefore, when using SSO, deactivating an account and blocking login on the SSO site will prevent mails indefinitely.)