Abuse & compliance · Email
Email sending runs on the shared abuse model in the Abuse & compliance overview: healthy traffic sends unrestricted, degraded reputation throttles your sending rate, and harmful signals pause it. This page covers which email signals drive that reputation, what we do about them automatically, and what you control. For the non-developer walkthrough of a send that has already been throttled, see Why was my sending throttled or paused?.
The signals that drive reputation
We derive your email reputation from the same per-recipient events you already receive through webhooks and the events API, so you can watch exactly what we watch:
- Bounce rate: the share of your delivery attempts that bounce, across every bounce class. Hard bounces (the address does not exist) do the most damage. A high rate is the signature of a purchased, scraped, or badly stale list, and it is the signal mailbox providers punish hardest.
- Complaint rate: the share of delivered mail reported as spam, arriving as email.complained through mailbox-provider feedback loops. Complaints measure whether recipients wanted your mail at all.
- Unsubscribe behavior: email.unsubscribed for the in-body link and email.list_unsubscribed for the provider's one-click button. Opt-outs are a normal part of list life, but a spike on one campaign is an early warning that your targeting or your consent has drifted. Recipients who cannot find the unsubscribe link report spam instead.
Tracking your own bounce and complaint rates per campaign is the surest way never to meet the throttle at all.
Indicative thresholds
These are guidance rather than contract: enforcement weighs volume, history, and trend, so a small test batch with two bounces is treated differently from a million-recipient campaign at the same rate.
- Healthy lists keep bounce rates below 1%. A sustained climb past that draws scrutiny well before the Metrics dashboard's 5% risk line, and mailbox providers degrade your inbox placement before we intervene.
- Complaint rates need to stay well under 0.3%, the ceiling Gmail and Yahoo enforce for bulk senders. Sustained rates above roughly 0.1% already cost you placement, and we throttle before your complaint rate damages the sending infrastructure other customers share.
Planning an unusual send, a re-engagement campaign to an old segment or a list migrated from another provider? Clean the list first, rather than letting the bounce rate discover the problem for you.
What happens automatically
Beyond throttling, we act on individual recipients as their signals arrive, so a bounce or complaint needs no work from you. Hard bounces suppress the address for all mail, while complaints and unsubscribes suppress it for non-transactional mail so password resets and receipts still arrive. Every automatic addition fires an email_suppression.created webhook event, and the Suppressions guide has the full policy, the record schema, and the management API.
Suppression is what stops one bad signal per address from costing you twice: a later send to that address is rejected before it reaches a mail server, so it never counts against your reputation again. Soft bounces and deferrals (email.deferred) have no reputation weight and no suppression, because they are transient failures we retry.
Your levers: list hygiene and consent
Throttling responds to signals, and the signals respond to how you build and maintain your list. Two practices prevent nearly every email pause:
- List hygiene: never import purchased or scraped lists, drop addresses that have not engaged in months, and validate addresses at collection time, because a typo'd signup is a future hard bounce. The list hygiene guide has the workflow.
- Consent: send only to recipients who asked, make unsubscribing a single obvious click, and keep marketing in the marketing category so suppression policy and unsubscribe handling apply to it. Most complaint spikes trace back to mail the recipient never opted into.
If sending is already paused, fix the source list before you request reinstatement. Resuming with the same list reproduces the same signals. The throttled-or-paused walkthrough covers the recovery path step by step.
Next steps
- Abuse & compliance overview: the channel-agnostic trust and safety pipeline and the throttle and pause model
- Suppressions: the four suppression reasons, the applies_to policy, and the management API
- Email events: full payloads for email.bounced, email.complained, the unsubscribe events, and bounce classification
- Why was my sending throttled or paused?: the non-developer walkthrough
- List hygiene: keeping bounce and complaint rates low in practice