Email providers
How each mail provider looks in DNS, how it answers an SMTP verification handshake, and what that means for the verdicts you get. One page per provider the Spaw MX classifier recognises.
- Amazon SES and Amazon WorkMail: MX records and email verification
How domains that receive mail through Amazon SES or WorkMail look in DNS, how they answer an SMTP verification handshake, and which verdicts to expect.
2026-10-08
- Barracuda Email Gateway Defense: MX records and email verification
How domains behind Barracuda look in DNS, how the gateway answers a verification handshake, and which verdicts to expect for Barracuda-protected addresses.
2026-10-07
- Fastmail: MX records and email verification
How Fastmail-hosted domains look in DNS, how Fastmail answers an SMTP verification handshake, and which verdicts to expect for Fastmail addresses.
2026-09-03
- GMX: MX records and email verification
How GMX domains look in DNS, how GMX answers an SMTP verification handshake, and which verdicts to expect for gmx.net, gmx.de and gmx.com addresses.
2026-10-07
- GoDaddy Workspace Email: MX records and email verification
How domains on GoDaddy's legacy Workspace Email look in DNS, how they answer a verification handshake, and why most GoDaddy email now classifies as Microsoft.
2026-10-07
- Google Workspace and Gmail: MX records and email verification
How Google-hosted domains look in DNS, how Gmail answers an SMTP verification handshake, and which verdicts and reasons to expect for Google addresses.
2026-09-03
- HEY: MX records and email verification
How HEY and HEY for Domains addresses look in DNS, how HEY answers a verification handshake, and which verdicts to expect for hey.com and custom domains.
2026-09-03
- Mailgun inbound routes: MX records and email verification
How domains that route inbound mail through Mailgun look in DNS, why Mailgun routes accept every recipient, and which verdicts to expect for addresses on them.
2026-10-07
- Microsoft 365, Outlook.com and Exchange Online: MX records and email verification
How Microsoft-hosted domains look in DNS, why many Microsoft 365 tenants answer as catch-all, and which verdicts to expect for Outlook and Exchange addresses.
2026-10-07
- Mimecast: MX records and email verification behind a security gateway
How domains behind Mimecast look in DNS, why a security gateway usually answers as catch-all, and which verdicts to expect for addresses protected by Mimecast.
2026-10-07
- Proofpoint: MX records and email verification behind a security gateway
How domains behind Proofpoint Essentials and Proofpoint Protection look in DNS, why the gateway usually answers as catch-all, and which verdicts to expect.
2026-10-07
- Proton Mail: MX records and email verification
How Proton-hosted domains look in DNS, how Proton Mail answers a verification handshake, and which verdicts to expect for proton.me and custom domains.
2026-10-07
- Rackspace Email: MX records and email verification
How Rackspace-hosted domains look in DNS, how Rackspace Email answers an SMTP verification handshake, and which verdicts to expect for addresses on it.
2026-10-07
- Tuta (Tutanota): MX records and email verification
How Tuta-hosted domains look in DNS, how Tuta answers a verification handshake, and which verdicts to expect for tuta.com, tutanota.com and custom domains.
2026-09-03
- Yahoo Mail and AOL: MX records and email verification
How Yahoo and AOL domains look in DNS, why their servers often leave a verification handshake unverified, and which verdicts to expect for those addresses.
2026-09-03
- Yandex 360 and Yandex Mail: MX records and email verification
How domains on Yandex 360 for Business look in DNS, how Yandex answers an SMTP verification handshake, and which verdicts to expect for Yandex-hosted addresses.
2026-10-07
- Zoho Mail: MX records and email verification
How Zoho-hosted domains look in DNS, how Zoho answers an SMTP verification handshake, and which verdicts to expect for Zoho Mail addresses.
2026-09-03
- iCloud Mail: MX records and email verification
How iCloud Mail and iCloud custom domains look in DNS, how Apple's servers answer a verification handshake, and which verdicts to expect.
2026-10-07
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