# Send email that lands

> Newsletters, outreach and the authentication that keeps you out of spam.

- [Google email sender guidelines](https://find.do/t/google-email-sender-guidelines/) ◆ official — The rules Gmail applies to bulk senders — authentication, unsubscribe, spam rate. (free; support.google.com)
- [beehiiv](https://find.do/t/beehiiv/) — Newsletter platform built around growth — referrals, recommendations, ad network. (free tier; beehiiv.com)
- [Buttondown](https://find.do/t/buttondown/) — A minimal, developer-friendly newsletter tool with Markdown and an API. (free tier; buttondown.com)
- [Instantly](https://find.do/t/instantly/) — Cold-email sending with mailbox warm-up and rotation. (paid; instantly.ai)
- [Kit (formerly ConvertKit)](https://find.do/t/kit/) — Creator email with automations, landing pages and commerce. (free tier; kit.com)
- [MXToolbox](https://find.do/t/mxtoolbox/) — Checks SPF, DKIM, DMARC, MX and blacklists for a domain. (free tier; mxtoolbox.com)
- [NeverBounce](https://find.do/t/neverbounce/) — Email list verification to keep bounces under control. (paid; neverbounce.com)
- [Substack](https://find.do/t/substack/) — Newsletter publishing with a built-in discovery network and paid tiers. (free tier; substack.com)

Each tool page has a Markdown twin at its URL + `index.md`.