Blocking, disabling, deleting
Three different things, and picking the wrong one is the most common mistake people make with an alias service.
Blocking a sender
One contact has gone bad, the rest of the alias is fine. Block them and their mail stops; everything else keeps arriving.
Use this when a legitimate service starts sending you things you did not ask for, but you still want mail from the alias generally.
Disabling the alias
Mail to it is refused, but the alias still exists and still belongs to you. Turn it back on whenever.
Use this for a burner you are done with but might need again, or when something is being abused and you want to think about it rather than act.
Deleting
The alias stops working permanently. It goes to the trash for 30 days first, so a mistake is recoverable, and after that it is gone.
The address is never reused. Not by you, not by anyone else. We keep a record of every deleted address specifically to refuse it in future. If we recycled addresses, whoever got yours next would receive your password resets.
That is also why deleting is not a way to free up a slot on the free plan without consequence: the address is spent.
Burner aliases
Set an expiry when you create one and it stops on its own. Useful for a one-time signup where you know you will never want the mail again, and better than a reminder to yourself that you will not action.
Writing to someone first
A masked reply address only exists after someone has written to you. To start the conversation yourself, create a reverse alias for their address from the alias detail page: you get an address to send to, we translate it, and they see your alias.
The alias needs a mailbox for this, for the same reason replies do. Inbox-only aliases compose from the web instead.
Something here wrong or missing? Tell us. These pages live in the same repository as the code, so a correction is a one-line change.