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addy.io vs Email Spam Tester

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

addy.io compared with Email Spam Tester
Detailaddy.ioEmail Spam Tester
What it doesFree, open-source anonymous email forwarding Test real inbox placement and 42 technical checks with no signup required
StageNot given Established
FoundedNot given 2026
Based inNot given Not given
Pricing modelfreemium freemium
PricingFree plan with unlimited standard aliases but limited features. Lite plan at $1/month (billed yearly) adds custom domains and additional usernames. Pro plan at $3/month (billed yearly) or $4/month (billed monthly) includes unlimited shared domain aliases and 20 custom domains. Family and Duo plans a Not given
Key features
  • Browser extension for Firefox, Chrome, Edge, Safari
  • Custom domain support
  • Random alias generation
  • Multiple recipients per alias
  • Developer API for automation
  • Tracking pixel blocking
  • Rules and alias deactivation
  • Real inbox placement testing in Gmail, Outlook, Yahoo and more
  • 42 technical checks across authentication, infrastructure, content and compliance
  • SPF, DKIM and DMARC verification
  • Blocklist lookup across 20+ DNS blocklists
  • SpamAssassin-compatible spam score
  • Link reputation checking
  • HTML structure analysis
  • Bulk sender rules for Gmail and Yahoo compliance
  • Fix plan with recomputed score for corrections
  • API and MCP server integration options
What makes it different
  • Completely free and open-source software
  • Unlimited standard aliases on free plan
  • Reply and send from aliases without revealing real email
  • Easy alias management with deactivation instead of bounce
  • Multiple app platforms including self-hosted options
  • Two independent spam engine scores instead of one, including Gmail and Yahoo 2024 bulk sender rules
  • Fix plan recomputes points by scoring corrected message rather than estimating
  • No account, signup or credit card required to run tests
  • Built by practitioner with years of live sending infrastructure debugging experience
Free planNot given Not given
Open sourceNot given Not given
PlatformsNot given Not given
Public APINot given Not given
Community votes00
DR (Domain Rating by Ahrefs)61 no change since last check18 no change since last check
Trust Flow (Majestic)3117
Citation Flow (Majestic)4025
Referring domains (Majestic)145635

4 details filled in for both companies.

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