Companies / Buttondown / Slack
Does Buttondown use Slack?
Yes
We hold strong evidence for this.
- The company names it in its own subprocessor list, a statement that this vendor handles its customers' data.
How we know
About Buttondown
Buttondown is an email platform for sending newsletters, with automations, personalization, an editor, and an API. It serves both individual creators and businesses with large teams.
Summarized from its homepage on 5 Nov 2026.
What else Buttondown uses
Buttondown has evidence for 13 vendors. The strongest:
Cloudflare
Stripe
Amazon Web Services
Google Workspace
Heroku
Mailgun
Plain
Postmark
Sentry
Other companies using Slack
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- Every company and vendor, with its public source
- 100 API calls a month, plus MCP and the Chrome extension
- Work email only. No card, no sales call