Free Email Provider Detection

Identify email addresses from known free email providers (Gmail, Outlook, Yahoo, QQ Mail, etc.) by checking the domain against a curated blocklist.

Unlike disposable email detection, the SMTP verification still proceeds after detecting a free email provider — it only marks the address as free without skipping further checks.

Usage

smtp-probe verify user@gmail.com --free

The result will include a Free field indicating the matched source:

   Free       : ⚠ Yes (source: dpup)

Data Source

smtp-probe uses the community-maintained free email provider list from dpup/freemail:

The list includes all major global and regional free email providers: Gmail, Outlook, Yahoo, iCloud, GMX, Yandex, QQ Mail, 163 Mail, ProtonMail, Zoho, and thousands more.

The default source is downloaded automatically on first use.

Managing Lists

# List all sources and their status
smtp-probe freemail list

# Download the default source
smtp-probe freemail download

# Download specific sources
smtp-probe freemail download dpup

# Download all available sources
smtp-probe freemail download --all

# Update stale lists (re-downloads if older than 7 days)
smtp-probe freemail update

# Install daily auto-update via crontab
smtp-probe freemail update --install-cron

Where Lists Are Stored

Downloaded lists are saved at ~/.smtp-probe/freemail/ and loaded into a hash map for O(1) domain lookups at runtime.

Comparison: Disposable vs Free Email