Make sure the mail you send is really yours, and provably so.
SPF lists who may send as you, DKIM signs what you send, and DMARC tells receivers what to do when either fails. Check each one, build the records, or run everything at once.
SPF checker Include tree and the 10-lookup limit.SPF generator One record for every service, counted live.DMARC checker RFC 9989 tree walk, policy and reports.DMARC generator Start at p=none, step up with t=y.DMARC report reader Drop in .xml, .gz or .zip. Nothing is uploaded.DKIM checker Common selectors or yours; key size.MTA-STS and TLS-RPT Policy file fetched and matched to MX.Domain Health Report All of it at once, graded, with the fix.
SPF for sending services lookup cost measured by peekip
18 services| Service | Include | Goes on | Lookups | Measured |
|---|---|---|---|---|
| Google Workspace | _spf.google.com | your domain | 1 | 2026-11-05 |
| Microsoft 365 (Exchange Online) | spf.protection.outlook.com | your domain | 1 | 2026-11-05 |
| Zoho Mail | zohomail.com | your domain | 2 | 2026-11-05 |
| GoDaddy email and hosting | secureserver.net | your domain | 3 | 2026-11-05 |
| Proton Mail | _spf.protonmail.ch | your domain | 2 | 2026-11-04 |
| Fastmail | spf.messagingengine.com | your domain | 1 | 2026-11-05 |
| iCloud+ Custom Email Domain | icloud.com | your domain | 5 | 2026-11-05 |
| Hostinger Email | _spf.mail.hostinger.com | your domain | 3 | 2026-11-05 |
| SendGrid (Twilio) | sendgrid.net | a subdomain | 2 | 2026-11-05 |
| Mailgun | mailgun.org | your domain | 5 | 2026-11-04 |
| Amazon SES | amazonses.com | a subdomain | 1 | 2026-11-04 |
| Postmark | spf.mtasv.net | a subdomain | 1 | 2026-11-01 |
| Marketo Engage (Adobe) | mktomail.com | your domain | 1 | 2026-11-05 |
| Zendesk | mail.zendesk.com | your domain | 1 | 2026-11-04 |
| Freshdesk | email.freshdesk.com | your domain | 7 | 2026-11-05 |
| OCI Email Delivery (Oracle Cloud) | rp.oracleemaildelivery.com | your domain | 2 | 2026-11-05 |
| Cloudflare Email Routing and Email Service | _spf.mx.cloudflare.net | your domain | 1 | 2026-11-05 |
| Forward Email | spf.forwardemail.net | your domain | 5 | 2026-11-05 |
Lookups count the include itself plus everything nested in it (RFC 7208 §4.6.4), measured over DNS-over-HTTPS. Each service’s include is taken from its own documentation, linked on its page.