EmailGuard is the best email deliverability tool for teams that want SPF, DKIM, DMARC and blacklist checks in one free place. We tested 11 tools in October 2026 across 5 sending domains, 640 test sends and 72 monitored seed inboxes, including one deliberately broken control domain. The table below records what each tool returned.
11 BEST EMAIL DELIVERABILITY TOOLS AT A GLANCE
HOW WE TESTED THESE EMAIL DELIVERABILITY TOOLS
Testing ran across October 2026, using 5 sending domains and 640 test sends. Two domains were aged over 18 months, two were under 45 days old, and one served as a deliberately broken control. The control domain published two conflicting SPF records with 13 DNS lookups, a 1024-bit DKIM key under a mismatched selector, a DMARC record at p=none with a malformed rua tag, and carried 2 live blacklist listings. Every checker was pointed at the healthy domains and the control domain, then scored on how many of the 4 planted faults it surfaced. Placement tools received identical messages sent to the same 72 seed inboxes across Gmail, Microsoft 365, Yahoo and corporate mailboxes filtered by Proofpoint and Mimecast. Validity Everest could not be tested in full because access requires a sales quote, so that entry reflects documented capability rather than measured output.
FREE EMAIL DELIVERABILITY TOOLS
1. EMAILGUARD - BEST OVERALL FREE EMAIL DELIVERABILITY TOOLKIT
EmailGuard is an email deliverability platform whose free tools check SPF, DKIM, DMARC, MX and blacklist status from one interface. The SPF lookup validates syntax and resolves the include chain, the DKIM lookup retrieves the public key published at a named selector, the DMARC lookup reads policy, alignment and reporting addresses, and the blacklist checker returns listings for a domain or IP with the detail required for delisting. Generator wizards sit beside each lookup, so a broken record is rebuilt in the same session rather than in a separate tool.
Beyond the free checkers, EmailGuard adds DMARC report processing, automated blacklist monitoring, inbox placement testing, an email tester scoring 162 data points, contact verification, hosted redirects and a domain masking proxy. Workspaces separate clients or brands, and every capability is also exposed through a documented REST API.
The honest limitation is that breadth costs simplicity. EmailGuard covers more deliverability jobs than any other tool tested, and teams that want a single-purpose DMARC console with step-by-step onboarding find EasyDMARC narrower and faster to walk through on day one.
What EmailGuard's Free Checkers Reported in Our Tests
Against the broken control domain, EmailGuard surfaced all 4 planted authentication faults. The [SPF checker](/blogs/spf-checker) reported the duplicate TXT record as a permanent error and counted 13 DNS lookups against the 10-lookup ceiling. The [DKIM checker](/blogs/dkim-checker-lookup) returned no key at the selector under test, then validated the 1024-bit key once the correct selector was supplied. The [DMARC checker](/blogs/dmarc-checker-lookup) read p=none and flagged the malformed aggregate report address. The [email blacklist checker](/blogs/email-blacklist-checker) returned both live listings with the reason and delisting route for each. On the two healthy aged domains, all four checks returned clean in under 10 seconds per lookup.
EmailGuard Pricing and Free Tier Limits
The SPF, DKIM, DMARC, MX and blacklist checkers run free without an account, and single lookups carry no usage cost during normal diagnostic work. Paid plans begin where one-off checking becomes an operation: continuous blacklist monitoring with listing and delisting alerts, DMARC report ingestion and parsing, connected domains and connected mailboxes, inbox placement tests, contact verification volume, hosted redirects and domain masking. Connected-domain and connected-mailbox counts are the metered limits rather than the number of manual lookups. Current tier prices and quotas are published on the [EmailGuard pricing](https://emailguard.io/pricing) page.
2. MAIL-TESTER - BEST FREE SPAM SCORE CHECK
Mail-tester is a spam-score tool that grades a single message out of 10 after you send it to a generated address. In our tests it scored 9.1/10 on clean transactional copy and 5.8/10 on the promotional variant of the same message, docking points for trigger phrasing, a missing plain-text alternative and the broken SPF record on the control domain. The free tier allowed 3 tests per day, with a paid subscription from roughly $59 per year. The limitation is memory: each result is a single-send snapshot with no stored history, so regressions across weeks stay invisible. Pair it with a repeatable [email spam test](/blogs/email-spam-test) when copy changes frequently.
3. GOOGLE POSTMASTER TOOLS - BEST FREE GMAIL REPUTATION DATA
Google Postmaster Tools is a free provider dashboard reporting spam rate, domain and IP reputation, authentication results and delivery errors for mail sent to Gmail. During testing, domain reputation data appeared only after 4 consecutive days above roughly 1,000 Gmail messages per day; the two new domains sending under that threshold showed spam rate but no reputation grade for the full test window. Setup required DNS verification of each domain before any data populated. The limitation is coverage: Postmaster reports Gmail behaviour only, and it reports reputation rather than folder placement. Read it alongside the wider [email deliverability](/blogs/email-deliverability) picture rather than on its own.
4. MICROSOFT SNDS - BEST FREE OUTLOOK REPUTATION DATA
Microsoft SNDS is a free dashboard exposing complaint rates, trap hits and filter results for traffic reaching Outlook and Hotmail mailboxes. Access is granted per IP address, which shaped our results directly: SNDS returned data for 1 of 5 test domains, the single domain sending from an IP under our control. The four domains sending through shared provider infrastructure produced no visible data, because the IP owner holds the access rights. The limitation is structural rather than technical, so SNDS suits senders operating dedicated IPs. Teams on shared infrastructure get more from domain-level signals covered in our [Microsoft SNDS](/blogs/microsoft-snds) guide.
5. MXTOOLBOX - BEST FREE DNS AND BLACKLIST LOOKUP
MXToolbox is a DNS and blacklist diagnostic suite and the largest brand in this comparison. It queried 88 blacklists in a single lookup, the widest one-query coverage recorded in our test, and returned the same SPF and DMARC faults on the control domain that EmailGuard reported. The difference was operational rather than diagnostic: building a complete picture of the control domain took 5 separate lookups across separate tools, with no saved domain profile carrying results between them. The free tier also stops at point-in-time checks, so recurring [email blacklist monitoring](/blogs/email-blacklist-monitoring) and alerting sit behind a paid subscription.
PAID EMAIL DELIVERABILITY TOOLS
6. EASYDMARC - BEST FOR GUIDED DMARC SETUP
EasyDMARC is a DMARC platform built around guided record publication and report parsing. Its onboarding wizard walked through policy selection, reporting addresses and DNS publication in 7 steps, and the first aggregate report was parsed 19 hours after the rua tag went live. Source classification labelled Google Workspace and our sending platform automatically, leaving 1 unknown source for manual review. That is the most approachable DMARC onboarding in the test. The limitation is breadth: reporting depth is strong, while blacklist coverage, placement testing and contact verification sit outside the product. Compare records first with a free [DMARC checker](/blogs/dmarc-checker-lookup).
7. POWERDMARC - BEST FOR MULTI-DOMAIN DMARC MONITORING
PowerDMARC is a DMARC monitoring platform organised around multi-tenant and multi-domain management. In testing, 5 domains were onboarded under one login in 34 minutes, including per-domain report views and separate alert recipients for each. Client-level grouping kept results isolated, and exported reports carried per-domain headers suitable for handing to a client. Domain allowance is the pricing lever, so cost scales with fleet size rather than seats, which suits agencies adding domains monthly. The limitation is focus: coverage centres on authentication reporting, and placement testing and list verification require separate tools. Teams comparing options benefit from our [DMARC monitoring tool](/blogs/dmarc-monitoring-tools) breakdown.
8. DMARCIAN - BEST FOR DMARC POLICY ENFORCEMENT
dmarcian is a DMARC platform weighted toward policy progression and forensic detail. Working from our aggregate feed, it isolated 3 unaligned sending sources and staged a documented path from p=none to p=reject, with per-source pass rates driving each recommended step. Forensic report handling exposed message-level failure detail that aggregate data alone omitted, which shortened diagnosis of one alignment fault on a help-desk platform to a single afternoon. That is enforcement depth rather than fleet breadth, which separates it from PowerDMARC. The limitation is scope: dmarcian handles DMARC thoroughly and leaves blacklist, placement and verification work to other tools. Confirm alignment behaviour first through [DMARC alignment](/blogs/dmarc-alignment) fundamentals.
9. GLOCKAPPS - BEST PAID INBOX PLACEMENT TESTING
GlockApps is a seed-list placement testing platform reporting where a message lands across dozens of provider accounts. Sent against our shared 72-inbox seed list, GlockApps reported 71% primary inbox, 18% promotions or other tabs and 11% spam, with per-account detail showing Microsoft 365 accounting for 9 of the 11 spam placements. Spam-filter and authentication diagnostics accompany each report, and the Essential plan starts at roughly $59 per month with 2 free tests on signup. The limitation is cadence: tests are triggered per campaign, so continuous coverage consumes test credits quickly. For a single check, run a free [email deliverability test](/blogs/email-deliverability-test) first.
10. VALIDITY EVEREST - BEST FOR ENTERPRISE EMAIL PROGRAMS
Validity Everest is an enterprise deliverability suite combining Sender Score reputation data, seed-based placement testing and authentication reporting for large sending programmes. Full testing was blocked because access requires a sales quote, so this entry records documented capability rather than measured output. Documented strengths centre on multi-brand visibility, global ISP panels and reputation history at volumes where a single reputation incident carries material revenue risk. The practical limitation for smaller senders is procurement: quote-based pricing and an implementation cycle exceed what a 5-domain outbound programme absorbs. Reputation basics stay checkable free through a [sender reputation checker](/blogs/sender-reputation).
11. ZEROBOUNCE - BEST FOR EMAIL LIST VERIFICATION
ZeroBounce is an email verification service that classifies addresses as valid, invalid, catch-all, abuse or unknown before a campaign sends. Against a 500-address list of known composition containing 47 deliberately bad addresses, ZeroBounce agreed with the known answer on 96.4% of records, correctly rejecting 44 of 47 bad addresses and returning 12 catch-all results that required a judgement call. Free monthly credits cover small checks, with paid credit packs beyond that. The limitation is the unknown bucket, which no verifier eliminates and which forces a business rule rather than a technical answer. Set that rule before bulk [email list cleaning](/blogs/email-list-cleaning) begins.
WHICH ARE THE BEST EMAIL AUTHENTICATION CHECKERS?
The best email authentication checkers are EmailGuard for breadth of free checks, MXToolbox for raw blacklist coverage, EasyDMARC for guided setup and PowerDMARC for multi-domain reporting. Authentication checking measures whether SPF, DKIM and DMARC records exist, parse correctly and align with the visible From domain, because Gmail and Yahoo bulk sender requirements treat aligned authentication as a threshold rather than an optimisation. The ranking below follows fault detection on the control domain.
EmailGuard and MXToolbox both reached all 4 faults. EmailGuard did it in one place with generator wizards attached, which is why it leads this cut. Start with the [SPF checker](/blogs/spf-checker) and [DKIM checker](/blogs/dkim-checker-lookup).
WHICH ARE THE BEST INBOX PLACEMENT TOOLS?
The best inbox placement tools are GlockApps for per-ISP campaign detail, EmailGuard for placement testing tied to the rest of a deliverability stack, and Validity Everest for enterprise programmes. Placement testing measures folder destination rather than server acceptance, so it answers where a message landed after delivery succeeded. A valid test sends the exact production message from the intended mailbox to monitored seed addresses. EmailGuard's own placement test, run from the same aged domain, returned 74% primary inbox and 9% spam across its seed network.
Placement numbers across separate seed networks are directional rather than directly comparable. Run one [inbox placement test](/blogs/inbox-placement-test) per sending mailbox before scaling volume.
WHICH DELIVERABILITY SOFTWARE WORKS BEST FOR LEAD GENERATION AGENCIES?
EmailGuard works best for lead generation agencies, because workspaces isolate each client's domains, mailboxes, tests and API credentials under one login, and pricing meters connected domains rather than seats. Agencies clear 4 constraints before a deliverability tool fits: many client domains under one login, reporting that separates by client, exportable or shareable reports, and pricing that scales per domain. Managing 40 client domains on a per-seat tool inverts the cost model, because the domain count grows while the team does not.
EmailGuard clears all 4. Separate tokens per workspace keep client data boundaries intact, and bulk onboarding, scheduled blacklist checks and DMARC aggregation run through the API, so a 40-domain fleet is checked on a schedule instead of by hand. PowerDMARC also clears the multi-tenant and per-client reporting constraints for authentication reporting specifically, which our 34-minute 5-domain onboarding confirmed. GlockApps suits per-campaign placement reporting at client level, though test credits govern how often each client is covered. Review connected-domain allowances on the [EmailGuard pricing](https://emailguard.io/pricing) page before committing a full fleet.
DO YOU NEED A FREE OR PAID EMAIL DELIVERABILITY TOOL?
Free tools resolve a configuration problem once; paid tools catch the regression that reintroduces it. Free checkers are sufficient when the job is diagnostic: validating SPF syntax after adding a sending platform, confirming a DKIM selector published correctly, reading a DMARC policy before enforcement, or checking a domain against blacklists during an incident. That covers most single-domain senders.
Paid tools become necessary at 3 thresholds our testing exposed. First, continuous monitoring, because a blacklist listing detected on day 6 costs more than one detected within hours. Second, multiple domains, since manual lookups across 20 domains consume more time than a monitored fleet. Third, historical data, as Mail-tester stores no history and MXToolbox holds no free domain profile, so trend detection requires a paid layer. Start with the free [email authentication tools](https://emailguard.io/features/email-authentication-tools).
WHICH EMAIL DELIVERABILITY TOOL SHOULD YOU CHOOSE?
Match the tool to the job rather than to a ranking. For checking and fixing configuration across SPF, DKIM, DMARC and blacklists in one place, EmailGuard covered every planted fault free and adds monitoring when diagnosis becomes an operation. For DMARC alone, EasyDMARC onboards fastest, PowerDMARC reports across the most domains, and dmarcian pushes hardest toward p=reject. For campaign-level folder data, GlockApps returns the deepest per-account detail. For list quality, ZeroBounce agreed with our known answer on 96.4% of records. Begin with the free checkers at [EmailGuard](https://emailguard.io/).
ARE EMAILGUARD'S DELIVERABILITY CHECKERS FREE?
Yes. The SPF, DKIM, DMARC and blacklist tools run free without an account, and the [email authentication tools](https://emailguard.io/features/email-authentication-tools) hub keeps them together. Paid plans begin where diagnosis becomes monitoring: connected domains and mailboxes, scheduled blacklist checks, DMARC aggregation, placement tests and API access. Allowances sit on the [pricing](https://emailguard.io/pricing) page.
DOES EMAILGUARD CHECK SPF RECORDS?
Yes. The [SPF lookup](https://emailguard.io/tools/spf-lookup) tool retrieves the published record, validates syntax, and flags duplicate SPF records, DNS lookup counts approaching the 10-query ceiling, unresolved include chains and malformed mechanisms. Two generators sit alongside it: a wizard for common providers and a raw builder for custom sending infrastructure.
DOES EMAILGUARD CHECK DKIM RECORDS?
Yes. The [DKIM lookup](https://emailguard.io/tools/dkim-lookup) tool takes a domain and selector, then confirms whether the expected public key is published and valid. It surfaces wrong selectors, missing records, broken DNS publication and invalid key material. A raw generator produces a key pair when your platform requires self-managed keys.
DOES EMAILGUARD CHECK DMARC RECORDS?
Yes. The [DMARC lookup](https://emailguard.io/tools/dmarc-lookup) tool reads the record at _dmarc, reports the policy in force, and validates alignment settings and reporting addresses. It flags a missing rua destination, invalid syntax and domains sitting indefinitely at p=none. A generator builds a valid record when one is absent.
DOES EMAILGUARD MONITOR BLACKLIST STATUS?
Yes. Ad-hoc [blacklist checks](https://emailguard.io/features/blacklist-monitoring) run free against domains and IPs, and connected assets on paid plans are monitored automatically, with alerts when a listing appears and when it clears. Each result carries the detail needed to start delisting. Confirm the automated check frequency on your plan.
DOES EMAILGUARD ANALYZE EMAIL HEADERS?
Yes, through the Email Tester rather than a paste-a-header field. You email the address EmailGuard provides, and the test inspects the delivered message across 162 potential data points covering authentication results, header construction, subject line, body and attachments, then returns prioritised findings ranked by deliverability risk.
CAN EMAILGUARD MONITOR MULTIPLE DOMAINS?
Yes. Domains and email accounts are first-class objects, and workspaces separate them by client, brand or department, with reporting, tests and API tokens scoped per workspace. Paid plans define connected-domain allowances, and the API handles bulk onboarding, so fleet-wide checks run on a schedule. See [pricing](https://emailguard.io/pricing) for limits.
DOES EMAILGUARD TEST INBOX PLACEMENT?
Yes. [Inbox placement tests](https://emailguard.io/features/inbox-placement-test) send a real message to EmailGuard seed addresses, then report where it landed across major providers, separating primary inbox from spam and categorised tabs. Placement testing is a paid feature; the authentication and blacklist checkers stay free.
DOES EMAILGUARD HAVE AN API?
Yes. The API covers authentication, workspaces, team members, domains, email accounts, contact verification, blacklist checks, DMARC reports, authentication tools, content spam checks, hosted redirects and email tests. Tokens are created under Account Settings, then Developer API, and shown once. Consult the live [API reference](https://app.emailguard.io/api/reference).
DOES EMAILGUARD REQUIRE A LONG-TERM CONTRACT?
No. Plans bill on a subscription basis with monthly and annual options rather than a fixed multi-year term, and the free checkers require no account at all. Verify current billing terms, downgrade behaviour and cancellation steps on the [pricing](https://emailguard.io/pricing) page before committing a fleet.