Exclaimer

aid: exclaimer
name: Exclaimer
description: Exclaimer is an email signature management platform used by IT, marketing, and sales teams to centrally create,
  deploy, and govern corporate email signatures across Microsoft 365, Microsoft Exchange, and Google Workspace. It manages
  signatures for more than 9 million email accounts, adding campaign banners, meeting-branding backgrounds, click-tracking
  analytics, directory synchronization with Azure AD and Google Directory, and role-based access control. Exclaimer publishes
  the Exclaimer Cloud API — a partner/distributor provisioning REST API documented at cloudapi.exclaimer.com with a machine-
  readable OpenAPI 3.0.1 definition covering subscriptions, MSP subscriptions, subscription users, resellers, end users, mailbox
  counts, subscription transfers and reference data. It operates a multi-region Exclaimer Cloud with a real-time status page
  and a strong security and compliance program (SOC 2 Type II, ISO 27001/27018, HIPAA, PCI DSS, CSA STAR, Cyber Essentials).
accessModel:
  pricing: unknown
  onboarding: approval
  trial: false
  try_now: false
  public: false
  label: Requires approval
  confidence: medium
  source: []
  generated: '2026-07-22'
  method: derived
image: https://exclaimer.com/img/og-image.jpg
url: https://raw.githubusercontent.com/api-evangelist/exclaimer/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- insight-partners
x-tier: enriched
x-tier-reason: 'Promoted from stub 2026-08-13: the Exclaimer Cloud API and its OpenAPI 3.0.1 were discovered and captured,
  with 22 artifacts wired.'
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-08-13'
tags:
- Company
- Email
- Email Signatures
- Email Signature Management
- Microsoft 365
- Google Workspace
- Marketing
- Productivity
- SaaS
- Security
apis:
- name: Exclaimer Cloud API
  description: Partner and distributor provisioning API for Exclaimer Cloud tenants. Covers creating and managing subscriptions
    (add, update, activate, deactivate, end, reactivate, migrate, transfer ownership, change SKU/tier/NFR status), MSP subscriptions
    and sender usage export, subscription users and roles, resellers, end users, mailbox counts and allocation, and reference
    data (data centers, SKUs, tiers). REST over HTTPS with JSON, authenticated with an ExApiToken API key header, PascalCase-or-camelCase
    request tolerance, and ContinuationToken paging. Access is restricted to the Exclaimer distributor network; tokens are
    issued by Exclaimer.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - email-signatures
  - provisioning
  - subscription-management
  - partner-api
  - distributor
  - msp
  - reseller
  - saas-management
  properties:
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: OpenAPI
    url: openapi/exclaimer-subscriptions-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-msp-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-subscription-users-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-subscription-transfers-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-end-users-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-resellers-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-mailboxes-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-reference-resources-openapi.yml
  - type: OpenAPI
    url: openapi/exclaimer-miscellaneous-openapi.yml
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Overlay
    url: overlays/exclaimer-cloud-api-overlay.yaml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
  - type: AgentSkill
    url: skills/_index.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://exclaimer.com/
- type: Pricing
  url: https://exclaimer.com/pricing/
- type: Blog
  url: https://exclaimer.com/blog/
- type: SignUp
  url: https://go.exclaimer.com/trial
- type: HelpCenter
  url: https://support.exclaimer.com/hc/en-gb
- type: TermsOfService
  url: https://exclaimer.com/legal/website-terms-of-use/
- type: PrivacyPolicy
  url: https://exclaimer.com/legal/privacy-policy/
- type: StatusPage
  url: https://status.exclaimer.com/
- type: Lifecycle
  url: lifecycle/exclaimer-lifecycle.yml
- type: Compliance
  url: https://exclaimer.com/product/security/
- type: TrustCenter
  url: security/exclaimer-trust-center.yml
- type: Security
  url: https://vdp.exclaimer.com/p/Welcome
- type: VulnerabilityDisclosure
  url: security/exclaimer-vulnerability-disclosure.yml
- type: SecurityTxt
  url: well-known/exclaimer-security.txt
- type: WellKnown
  url: well-known/exclaimer-well-known.yml
- type: DomainSecurity
  url: security/exclaimer-domain-security.yml
- type: DeveloperPortal
  url: https://cloudapi.exclaimer.com/
- type: Documentation
  url: https://support.exclaimer.com/hc/en-gb
- type: APIReference
  url: https://cloudapi.exclaimer.com/
- type: GettingStarted
  url: https://support.exclaimer.com/hc/en-gb/articles/360050643511-Onboarding-Connect-to-Microsoft-365
- type: Support
  url: https://support.exclaimer.com/hc/en-gb
- type: GitHubOrganization
  url: https://github.com/exclaimerltd
- type: ChangeLog
  url: changelog/exclaimer-changelog.yml
- type: Deprecation
  url: https://exclaimer.com/support/discontinued/
- type: LLMsTxt
  url: llms/exclaimer-llms.txt
- type: Plans
  url: plans/exclaimer-plans-pricing.yml
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 22
  pass: local-v1
  note: Round 1 (2026-07-19) recorded "Exclaimer does not publish a public developer API reference". That was wrong. STEP
    0b contract discovery found the Exclaimer Cloud API reference at https://cloudapi.exclaimer.com/ — server-rendered, not
    a JS shell — with a real OpenAPI 3.0.1 served anonymously at https://cloudapi.exclaimer.com/openapi.json (HTTP 200, 39
    operations, 59 schemas). The docs are public; only the ExApiToken is gated to the distributor network.