Donaldson R F Email Provider Detector
See which provider each address belongs to — Gmail, Outlook, Yahoo, iCloud, Proton, UK internet providers and more — with a summary count.
How it works
Each address is looked up by its domain in a built-in list of more than 50 consumer mailbox services and internet-provider mail services. Anything else is labelled Other / own domain — usually a business, school or personal domain. The full result (every address with its provider and type) is in the CSV download; the page shows the first 200 rows.
The tool cannot see who hosts the mail for a custom domain. To check that, look at the domain’s MX records with the site’s DNS lookup.
Frequently asked questions
Does it detect Google Workspace or Microsoft 365?
No. A company domain that uses those services looks like any other own domain unless you inspect its MX records.
Which providers are known?
Gmail, Outlook/Hotmail/Live/MSN, Yahoo, iCloud, Proton, AOL, GMX, Zoho, Yandex, Mail.ru, Fastmail, Tuta, BT, Sky, Virgin Media, TalkTalk, Comcast, Orange and many more.
Is my list uploaded?
No. It stays in your browser.