Your sending reputation

Your Sapiom organization has one email sending reputation. Every inbox in the organization, on every domain, contributes to it. When its bounce or complaint rate crosses a threshold, sending is suspended for the whole organization until Sapiom support lifts it.

If you run a platform on Sapiom and send mail for your own customers from one organization, all of those customers share this reputation. One customer whose list bounces heavily can stop sending for every customer on your platform. Treat the rate as yours to manage.

How the rates are judged

The rates are computed over a rolling 24-hour window. Which rule applies depends on how many messages the organization sent in that window, counted per recipient.

Messages sent in the last 24h	Rate	Warning	Suspension
1,000 or more	Bounce rate	5%	10%
1,000 or more	Complaint rate	0.5%	1%
Under 1,000	Complaints	None	2 or more complaints once the complaint rate reaches 1%

• Permanent and transient bounces both count toward the bounce rate.
• A small sender is exposed. Under 1,000 sends, two complaints out of 200 messages suspend the organization.
• Mail sent from a custom domain builds its own reputation with mailbox providers such as Gmail and Outlook, but its bounces and complaints still count toward the organization’s rates.
• Sapiom does not notify you when a rate reaches the warning level. Watch the rates yourself.

What a suspension blocks

A suspension blocks outbound mail only:

Blocked	Keeps working
messages.send, reply, replyAll, forward	Inbound mail arrives in every inbox
inboxes.create	messages.list, messages.get, threads.*, and other reads
	Webhook delivery for received mail

An agent paused waiting for a reply still receives it. An agent that sends fails at the send step: the call throws EmailHttpError with HTTP 422 and body.error "agentmail_message_rejected". When the provider gives a reason, body.upstreamReason carries it. Retrying does not help; the send fails until the suspension is lifted.

Lifting a suspension

Contact Sapiom support to lift a suspension.

Reinstating the organization does not reset the 24-hour window. The bounces and complaints that caused the suspension still count, so the next bounce can suspend the organization again. Find and stop the cause before you ask for the lift: pause the sending agent, remove the bad addresses, or stop sending for the customer whose list caused it.

Suppressed addresses

Some events add the recipient to a suppression list automatically:

Event	Suppression entry
Permanent bounce	Added
Complaint (marked as spam)	Added
Unsubscribe	Added
Transient bounce	None

Suppression entries apply to the whole organization. An address suppressed because of mail sent for one of your customers is suppressed for all of them. Automatic entries cannot be removed through the API.

Watch the rates

GET /v1/email/metrics/rates returns the organization’s current bounce and complaint rates. These are the figures that suspension decisions are based on, and they cover every inbox in the organization. The read is free.

curl -sS https://agentmail.services.sapiom.ai/v1/email/metrics/rates \
  -H "x-sapiom-api-key: $SAPIOM_API_KEY"

{
  "bounceRate": 0.012,
  "complaintRate": 0.0005,
  "sent": 1840,
  "windowSeconds": 86400,
  "windowEnd": "2026-10-13T17:00:00.000Z"
}

Field	Meaning
bounceRate	Bounced over sent in the window, as a fraction: 0.05 is 5%. null when nothing was sent.
complaintRate	Complaints over sent in the window, as a fraction. null when nothing was sent.
sent	Messages sent in the window, counted per recipient.
windowSeconds	Length of the rolling window: 86400 (24 hours).
windowEnd	End of the window the rates cover, ISO 8601. The window advances hourly. null when there is no data yet.

Call it with your organization’s own API key. A key that belongs to any other tenant gets HTTP 403 with error: "agentmail_rates_internal_tenant_only", because the rates describe the whole organization.

Alert before the warning thresholds, so you have time to act before a suspension:

Rate	Warning threshold	Suggested alert
bounceRate	0.05	0.03
complaintRate	0.005	0.003

When sent is under 1,000, the bounce thresholds do not apply, but two complaints can suspend the organization. Alert on every new complaint at that volume. To see which inbox or customer a bounce or complaint came from, subscribe to the message.bounced and message.complained webhook events.

Sapiom sending limits

Sapiom applies its own limits on top of the reputation rules. See Email limits for the full rules.

Limit	Value
Recipient deliveries per inbox per day	200, resetting at 00:00 UTC
Addresses per recipient field per call	50 each in to, cc, bcc, and replyTo

Recommendations

• Verify recipients before sending. Assess each address with emailSearch.verifyEmail from Email Lookup, or another verification service, and drop the ones that fail. Unverified lists are the most common cause of bounces.
• Honor unsubscribes. Send List-Unsubscribe and List-Unsubscribe-Post headers on bulk mail, and stop sending to an address when its owner unsubscribes. A recipient who cannot unsubscribe tends to mark the mail as spam, which counts as a complaint.
• Send cold outreach from a custom domain. A custom domain keeps its mailbox-provider reputation separate from your other sending. Its bounces and complaints still count toward the organization’s rates, so verify those recipients too.

One customer can stop everyone's mail

In a platform that sends for many customers from one organization, gate each customer’s sending on their own bounce and complaint counts from webhook events. Pause a customer whose counts climb before the organization’s rate reaches the warning level.

Email Inboxes, send policy, limits, custom headers, and webhooks.

Email Lookup Find and verify addresses before you send.