Masked Email Manager
Guide
How to block a Fastmail Masked Email
Two ways to turn one off: Fastmail's own settings, or Masked Email Manager on your phone. Both update the same address in Fastmail.
In Fastmail
- Go to Settings, then Privacy & Security, then Masked Email.
- Find the address by the site or description you gave it.
- Set its state to Blocked. Delivery to your inbox stops immediately.
In Masked Email Manager
- Open the app and find the address in your list.
- Tap it to open the detail screen, then tap Disable.
- Or long-press the row and choose Disable from the menu, without leaving the list.
The row's state updates as soon as Fastmail confirms it, and the same toggle switches an address back to Active.
What blocking actually does
Mail sent to a blocked address stops arriving in your inbox and lands in Trash instead. Nothing bounces back to whoever sent it, so a service you disabled has no way to tell it happened. Switch the address back on and new mail goes back to arriving normally; what already landed in Trash stays there.
Block first, and decide later whether you ever want to hear from that address again.
Block, or delete?
Blocking is the reversible one: switch the address back on and delivery goes back to normal, though mail that arrived while it was blocked stays in Trash rather than moving to your inbox. Deleting is rougher: mail to it bounces right away, and deletion is something you do from Fastmail's own settings, not from this app. Fastmail keeps a list of deleted addresses you can restore from, but restoring doesn't bring back what bounced while it was gone, so treat deletion as a last resort rather than routine cleanup.
Block when a service might still matter to you later. Delete when it never will.
Making a new address instead? The create guide covers both places you can generate one.