Deactivate a domain

sithbit domain deactivate <domain> \
  [--active] \
  [--keypair <postmaster keypair>] \
  [--skip-preflight]

By default (no --active flag) this deactivates the domain. Deactivating a domain blocks sending and deleting mail for any mailbox that references it, and also blocks new registrations: creating a mailbox against the domain (or updating an existing mailbox to reference it) is refused while the domain is inactive, so deactivation both stops mail flow for a problem domain and retires it from new registrations until it is reactivated or closed.

Reactivating

Pass --active to flip a domain back to active:

sithbit domain deactivate sithbit.com --active

When a domain is retired for good rather than temporarily suspended, see Appendix: Closing accounts for domain close.