Skip to content
Skip to main content

Agent Account send pauses and abuse blocks

There are two cases where Nylas itself will stop an Agent Account from sending, separate from anything the recipient server does: a reputation-based pause triggered by a high bounce or complaint rate, and an abuse block applied by Nylas operations. Both are recoverable, but they surface differently in your application, and the recovery path is different.

For plan-level send quotas and outbound rule configuration, see Policies, Rules, and Lists. For general sender-reputation hygiene that applies to any mailbox, see Improving email delivery.

Bounce and complaint thresholds

Section titled “Bounce and complaint thresholds”

Nylas tracks the rolling bounce rate and complaint rate of mail sent from each Agent Account. When either rate climbs high enough, Nylas places the account under review; if the rate stays elevated, sending is paused until the issue is resolved. Nylas allows you to monitor deliverability in real time through the transactional webhook triggers described below — subscribe to them to see the same delivery, bounce, and complaint events the rate calculation is based on.

How the rates are measured

Section titled “How the rates are measured”
  • Bounce rate is hard bounces divided by your recent representative send volume. Only hard bounces to addresses that don’t exist count. Transient soft bounces — full mailbox, temporary rejections, greylisting — do not. The denominator is a recent volume window, not a fixed time period, so the rate stays meaningful whether you send a hundred messages a day or a million.
  • Complaint rate is the number of times a recipient clicks Mark this email as spam or moves your email into the junk folder, divided by your recent representative send volume. Complaints are counted only against recipient domains that send complaint feedback to senders.

Thresholds

Section titled “Thresholds”
Bounce rateAccount stateWhat happens
Under 2%HealthyNormal sending.
5% or aboveUnder reviewSending continues; sustained elevated bounces will lead to a pause.
10% or aboveSending pausedOutbound send requests fail until Nylas clears the pause.
Complaint rateAccount stateWhat happens
Under 0.1%HealthyNormal sending.
0.1% or aboveUnder reviewSending continues; sustained complaints will lead to a pause.
0.5% or aboveSending pausedOutbound send requests fail until Nylas clears the pause.

What “under review” and “paused” look like to your code

Section titled “What “under review” and “paused” look like to your code”

Under review is silent to your application, while pausing returns immediate feedback through the send response. Here are the response shapes you may see:

StatusResponse bodyCause
400 Bad RequestForwarded message from the underlying infrastructure (for example, text mentioning an account-level suspension or that sending is paused for the account)Reputation enforcement paused sending
400 Bad Request"domain is not verified"The from domain isn’t verified — finish verification in Provisioning and domains
429 Too Many Requests"rate limit exceeded"A per-account or per-domain rate limit was hit — back off and retry, or raise quotas via policy

Staying inside the envelope

Section titled “Staying inside the envelope”
  • Validate recipient addresses before sending, and skip any address that has hard-bounced before.
  • Honor unsubscribe and list-removal requests immediately. The complaint threshold (0.1%) is small enough that even a handful of recipients reporting your mail can put a low-volume account under review.
  • Use double opt-in for any list you care about.
  • Wire up the four message.transactional.* triggers and pause your own outbound logic if bounced, complaint, or rejected rates start climbing — you’ll see the problem in your own telemetry before Nylas tells you about it.
  • Authenticate your sending domain. Missing or misconfigured DKIM, SPF, or DMARC shows up as elevated bounces from recipient servers that refuse the mail outright.

Abuse-restriction blocks

Section titled “Abuse-restriction blocks”

Separately from reputation pauses, Nylas may apply an abuse restriction to a sender, sender domain, organization, application, or grant when our operations team identifies abusive or out-of-policy use. Active restrictions reject matching sends immediately. There is no threshold to stay under — restrictions are applied because of a signal we treat as abuse, not because of a quota you can wait out.

What you’ll see

Section titled “What you’ll see”

What the block can be scoped to

Section titled “What the block can be scoped to”

A restriction can target any of the following, and Nylas applies the most specific match:

  • A single sender email address
  • A sender domain, including its subdomains
  • An organization
  • An application
  • A specific Agent Account grant

A restriction at the application level affects every Agent Account grant under that application — not just the one you happened to send from.

How to recover

Section titled “How to recover”
  • Contact support. Include the application ID, the grant ID, and one example error response so the abuse team can locate the restriction and walk through what triggered it.
  • Once the underlying issue is resolved, Nylas operations disables the restriction. Send requests start succeeding on the next attempt — there’s no propagation delay you have to wait through.

What’s next

Section titled “What’s next”