Postmaster
Postmaster and network information
For mailbox providers, blocklist operators and network admins: where Groundmail sends from, what we send, and how to reach us.
What we send
Groundmail is a transactional email service. Customers send password resets, sign-in codes, receipts, alerts and opt-in product email from their own verified domains. We don't carry newsletters, bulk marketing or unsolicited mail, and our API rejects the newsletter category.
How we prevent abuse
New accounts verify their domain and add a payment method before they can send to anyone but themselves. Sending volume ramps up gradually, addresses that can't receive mail are held back, and bounces and complaints are suppressed automatically. Accounts with high bounce or complaint rates are paused.
Sending infrastructure
Groundmail runs its own mail servers. Outbound mail comes from 209.188.111.0/24. Every sending IP has matching forward and reverse DNS, and introduces itself with that hostname.
| IP address | Hostname |
|---|---|
| 209.188.111.10 | mta1.mail.groundmail.dev |
| 209.188.111.11 | mta2.mail.groundmail.dev |
| 209.188.111.12 | mta3.mail.groundmail.dev |
| 209.188.111.13 | mta4.mail.groundmail.dev |
| 209.188.111.15 | mta5.mail.groundmail.dev |
- SPF: customer domains include
spf.groundmail.dev. - DKIM: mail is signed with the customer's own domain.
- Bounces: return-path addresses are on the customer's domain or
rp.groundmail.dev. - We receive complaint feedback loops and act on every report.
Contacts
- Abuse reports: abuse@groundmail.dev. Please include the full message headers. We reply within one business day.
- Postmaster and deliverability: postmaster@groundmail.dev
Customers agree to our Acceptable Use policy and Terms of Service.