specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: MailPace
providerId: mailpace
created: '2026-06-20'
modified: '2026-06-20'
reconciled: false
tags:
- Email
- Transactional Email
- Messaging
- SMTP
- Privacy
- Rate Limiting
- Quotas
- Throttling
description: >-
  MailPace applies sending rate limits to protect deliverability when large
  volumes of email are sent over short periods. The send endpoint returns
  HTTP 429 Too Many Requests when limits are exceeded. Per-request structural
  limits also apply - a maximum of 50 recipients in the To field and a total
  message size of 50 MB. Specific numeric per-second/per-minute send rates are
  not published and are not reconciled in this artifact.
notes: >-
  Verify any account-specific send-rate ceilings with MailPace support during
  reconciliation; the documented hard limits are 50 recipients per request and
  50 MB total message size.
sources:
- https://docs.mailpace.com/reference/send/
- https://docs.mailpace.com/reference/responses/
responseCodes:
  throttled: 429
limits:
- name: Send Rate
  scope: account
  metric: emails
  limit: see provider documentation
  notes: Sending too many emails over a short window returns HTTP 429.
- name: Recipients Per Request
  scope: request
  metric: recipients
  limit: 50
  notes: Maximum of 50 addresses across the To field per send request.
- name: Message Size
  scope: request
  metric: bytes
  limit: 52428800
  notes: Total email size, including attachments, may not exceed 50 MB.
policies:
- name: Throttling Response
  description: Exceeding the send rate returns HTTP 429 Too Many Requests.
- name: Backoff Strategy
  description: Clients should implement exponential backoff with jitter and retry queued sends.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com