Suppression
The per-Org list of addresses sending is refused to — how bounces and complaints add to it automatically, how to suppress or release an address by hand, and why a suppressed send is refused rather than silently dropped.
The suppression list is the set of recipient addresses Longbridge refuses to send to on your behalf. It’s how the platform stops you mailing an address that has already hard-bounced or complained — the single most effective way to keep your bounce and complaint rates down, and your sending reputation intact.
Early access. Email is being rolled out behind an Org flag. If you don’t see it in the Console, it isn’t enabled for your organization yet.
It’s per Org
Your suppression list is yours. One Org’s bounce never blocks another Org from mailing the same address — a shared list would let one sender’s bad data quietly degrade everyone else’s reach. (A platform-wide upstream list exists as a last-ditch reputation backstop, but the product concept you manage is per-Org.)
How addresses get suppressed
An address lands on the list one of three ways. Each entry records which:
| Reason | Added when |
|---|---|
bounce | A message to the address permanently bounced — the address is dead or rejecting. Transient bounces (a full mailbox, a temporary failure) do not suppress. |
complaint | The recipient marked a message as spam. |
manual | You added it yourself (below). |
Bounce and complaint suppressions happen automatically, off the delivery feedback
that also drives the email.bounced and email.complained
webhook events. You don’t have to do anything for them to work.
A suppressed send is refused, not dropped
When you send to a suppressed address, the send is rejected at accept — a 400
whose body lists the offending addresses under suppressedAddresses (over SMTP, a
550 5.1.8 naming them). It is never silently black-holed. You always know a
message didn’t go out and exactly why, so a suppressed recipient can never look like
a successful send.
If a message has several recipients and one is suppressed, the send is rejected — remove the suppressed address (or release it, below) and send again.
Suppress an address by hand
Add an address yourself — to honor an unsubscribe, or to pre-empt a recipient you know you shouldn’t mail:
lbr email suppression add someone@example.comIt’s also available under Email → Suppression in the Console. A manual entry behaves exactly like an automatic one: sends to it are refused until you remove it.
Release an address
Removing a suppression makes the address deliverable again — the deliberate override for when you know a previously bad address is now good (the customer fixed their mailbox, or the bounce was a one-off misclassification):
lbr email suppression list
lbr email suppression remove <suppression-id>Important: Release an address only when you have a real reason to believe it now accepts mail. If it hard-bounces again, it’s re-suppressed automatically — and repeatedly mailing addresses that bounce is exactly what drives an Org toward the automatic sending pause. Removing a suppression doesn’t lower your bounce rate; it only lets you try the address once more.
Where to next
- Sending mail — where the suppression check happens.
- Quotas & limits — the bounce and complaint pauses suppression feeds.
- Webhooks — the bounce and complaint events behind automatic suppression.