Email Provider Detector
Detect the mailbox host and third-party senders for any domain by fingerprinting MX records and the SPF include chain.
About the Email Provider Detector
The Email Provider Detector fingerprints a domain's email stack from its DNS records. MX hosts reveal the mailbox provider — Google Workspace, Microsoft 365, Zoho, Proton, Fastmail, iCloud, Yandex — while SPF includes surface the third-party senders authorized to send on the domain's behalf: SendGrid, Mailgun, Amazon SES, Postmark, Mailchimp, Klaviyo, HubSpot, Zendesk and more.
This is the fastest way to understand how a company runs email without asking. Sales teams use it to qualify prospects (is this a G Suite shop? Are they on HubSpot?), security teams use it to inventory the SaaS platforms with a foothold on a domain, and DevOps teams use it during migrations to confirm the cutover completed cleanly.
Combine with our SPF Checker for policy validation, DMARC Checker for enforcement posture, and DKIM Checker to confirm each sender's signing key is published.
How to use this tool
- 1Enter the required value in the input field above (domain, IP, URL, or text depending on the tool).
- 2Click the action button to run the check — results are computed instantly from our edge network.
- 3Review the parsed output, key fields and any warnings shown in the result card.
- 4Copy the result, share the page URL, or jump to a related tool from the sidebar to continue debugging.
Key features
- Detects 10+ mailbox providers via MX fingerprinting
- Detects 9+ sender platforms via SPF include analysis
- Shows the raw MX priority list and SPF record
- Zero setup — works on any domain