# Postmark

Postmark is an email delivery service for developers that sends transactional and marketing email through an SMTP service and an API. It keeps transactional and broadcast mail on separate message streams, processes inbound email, and offers DMARC monitoring. ActiveCampaign acquired Postmark in May 2022.

Page: https://slateindex.ai/brand/postmark · data of 2026-11-02

## Facts

- Founded: 2010
- Company type: Division of ActiveCampaign
- Deployment: Cloud
- Best for: Developers and product teams that need reliable transactional email
- Compliance: GDPR

## Products

- Postmark transactional email (API and SMTP): Sends transactional email through a REST API or SMTP, with delivery and activity tracking.
- Message Streams: Separate sending infrastructure for broadcast and marketing email, kept apart from transactional mail.
- Inbound email processing: Turns inbound email into JSON and posts it to a webhook URL.
- DMARC Digests: DMARC monitoring that shows who sends email using your domain and helps fix authentication issues.

## Rankings

| Category | Rank | Visibility | Mentions |
|---|---|---|---|
| Email Marketing | 29 of 55 | 1.9 | 5 |

## By engine

| Engine | Visibility | Mention rate |
|---|---|---|
| chatgpt | 2.6 | 7.4% |
| google_ai_mode | 1.1 | 3.7% |
| perplexity | 1.9 | 7.4% |

## Definitions

- Visibility (0–100): how often and how high AI answers name the brand, weighted by position.
- Mention rate: share of collected AI answers that name the brand.
- Share of voice: the brand's mentions as a share of all brand mentions in the category.
- Citation authority: share of answers naming the brand that cite the brand's own site.

Cite as: SlateIndex, “Postmark AI visibility profile”, https://slateindex.ai/brand/postmark, data of 2026-11-02. Licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).