Free email deliverability tools compared
Quick answer: To check many domains at once for free, SimpleVerifier's bulk email authentication checker takes 100 domains a run with no account (500 signed in). For one domain, MxToolbox Email Health, EasyDMARC's Domain Scanner and SimpleVerifier's deliverability audit each check a single domain. mail-tester and Learndmarc test a real message you send, and Google Postmaster Tools shows Gmail reputation for verified domains.
By SimpleVerifier Team · Last updated · Prices and limits checked on each vendor’s own site
Side by side
Ranked by how many domains one free run checks without creating an account; tools that need an account count as 0.
| # | Tool | Domains per run, no account | Free limit | Bulk limit | Price | Signup needed | Best for |
|---|---|---|---|---|---|---|---|
| 1 | SimpleVerifier bulk email authentication checker | 100 | 100 domains a run; 500 with a Google sign-in | 500 domains a run (signed in) | Free | No (sign-in lifts the limit) | Agencies checking SPF, DKIM, DMARC and MX across many domains |
| 2 | SimpleVerifier deliverability audit | 1 | 1 domain a check, 10 checks a minute | 1 domain a run | Free | No | One domain's MX, SPF, DKIM, DMARC and blocklist status in one pass |
| 3 | MxToolbox Email Health | 1 | 1 Email Health check every 24 hours | 1 domain a check | Free; Delivery Center from $129/mo | Not stated; the page offers a free account | A broad one-domain report: blacklists, mail, web and DNS servers |
| 4 | EasyDMARC Domain Scanner | 1 | Free tool; no limit published | 1 domain a scan | Free; DMARC Plus from $35.99/mo billed yearly | No for on-page results; a form emails the report | SPF, DKIM, DMARC and BIMI for one domain |
| 5 | mail-tester | 1 | 3 tests in any 24 hours | 1 sent message a test | Free; extra test packs from 1 to 10 euros | No | Scoring a real message you send, including content and sending IP |
| 6 | Learndmarc | 1 | No limit published | 1 sent message a test | No price published | Not stated | Seeing step by step how a receiver evaluates SPF, DKIM and DMARC |
| 7 | Google Postmaster Tools | 0 | Dashboards for your verified domains | Every domain you verify | Free (Google's page states no price) | Yes (Google account and domain verification) | Seeing spam rate and reputation at Gmail for mail you already send |
| 8 | GlockApps | 0 | 2 spam test credits, 10,000 DMARC messages | Not published | Free plan; Essential $59/mo | Yes (free account) | Inbox placement tests across mailbox providers |
How we compared
We read each tool's own page on 19 October 2026 for what it checks, its free limit and whether it asks for an account, and list that page under each tool. Tools that test a sent message rather than a domain count one per test. We did not compare result quality, and we left out tools whose pages were down for maintenance that day.
Each tool in a few lines
1. SimpleVerifier bulk email authentication checker(our tool)
Best for: Agencies checking SPF, DKIM, DMARC and MX across many domains
- Pass, warn or fail per domain with the reason
- CSV download
- Watch out: DNS only: it does not send a test message or measure inbox placement
- Watch out: DKIM is found only on common selectors
Checked October 19, 2026: Bulk email authentication checker
2. SimpleVerifier deliverability audit(our tool)
Best for: One domain's MX, SPF, DKIM, DMARC and blocklist status in one pass
- Adds blocklist lookups to the DNS checks
- Watch out: One domain at a time
Checked October 19, 2026: Deliverability audit
3. MxToolbox Email Health
Best for: A broad one-domain report: blacklists, mail, web and DNS servers
- Runs many DNS, mail server and blacklist tests in one report
- Free account adds weekly blacklist monitoring for one domain
- Watch out: Free users get one Email Health check every 24 hours
Checked October 19, 2026: MxToolbox Email Health · MxToolbox plans
4. EasyDMARC Domain Scanner
Best for: SPF, DKIM, DMARC and BIMI for one domain
- Covers BIMI as well as SPF, DKIM and DMARC
- Watch out: Does not check MX or blocklists
Checked October 19, 2026: EasyDMARC Domain Scanner · EasyDMARC pricing
5. mail-tester
Best for: Scoring a real message you send, including content and sending IP
- Tests the actual message, mail server and sending IP, not just DNS
- Watch out: You must send a message to it for each test
Checked October 19, 2026: mail-tester FAQ · mail-tester micro-payment
6. Learndmarc
Best for: Seeing step by step how a receiver evaluates SPF, DKIM and DMARC
- Shows alignment and the final DMARC verdict visually
- Also accepts pasted headers
- Watch out: Explains authentication only; no blocklist or inbox placement data
Checked October 19, 2026: Learndmarc
7. Google Postmaster Tools
Best for: Seeing spam rate and reputation at Gmail for mail you already send
- The only source here of Gmail's own spam-rate data for your mail
- Watch out: Dashboards can be empty on days when your volume to Gmail is low
Checked October 19, 2026: Google: Postmaster Tools dashboards
8. GlockApps
Best for: Inbox placement tests across mailbox providers
- Measures inbox versus spam placement, which DNS checks cannot
- Watch out: The free plan has 2 spam test credits
Checked October 19, 2026: GlockApps pricing
Common questions
- How do I check SPF, DKIM and DMARC for many domains at once for free?
- SimpleVerifier's bulk email authentication checker takes up to 100 domains a run with no account, or 500 after a Google sign-in, and gives each a pass, warn or fail with a CSV download. The other free checkers in this list take one domain at a time.
- What is the difference between a DNS check and a mail test?
- A DNS check reads the records a domain publishes: SPF, DKIM, DMARC, MX. A mail test such as mail-tester or Learndmarc scores a real message you send, so it also sees the sending server, IP and content.
- Can a free tool tell me if my email lands in spam?
- Only partly. Inbox placement needs seed mailboxes, which GlockApps offers with 2 free test credits. Google Postmaster Tools shows Gmail's spam rate for your verified domain once you send enough mail.
- Do I need an account to use these tools?
- Not for SimpleVerifier's checkers, EasyDMARC's Domain Scanner or mail-tester. GlockApps and Google Postmaster Tools need an account. MxToolbox's page does not say whether its one free Email Health check a day needs one.