Email deliverability tools exist because sending an email and having it land in the inbox are two different problems. A RevOps team can have perfect list hygiene and a well-written sequence and still watch open rates collapse because of a misconfigured DMARC record or a domain that quietly slid into a spam filter’s bad graces. Here are 13 email deliverability tools worth bookmarking in 2026, covering authentication monitoring, inbox placement testing, warmup, and the free dashboards you should already be checking weekly.
1. Google Postmaster Tools
Google Postmaster Tools is free and effectively mandatory: it’s the only place that shows you exactly how Gmail, the mailbox provider most of your prospects use, sees your domain’s reputation, spam rate, and authentication status. It won’t test inbox placement across providers, but as a baseline health check it belongs at the top of every RevOps deliverability stack.
Best for: free, Gmail-specific reputation monitoring every sender should have running.
2. Mail-Tester
Mail-Tester gives you a quick spam score and a breakdown of authentication, content, and blacklist issues for a single email, for free or a few dollars a month for more checks. It’s not a monitoring tool, more a fast sanity check before a big send, but that immediacy makes it useful when you’ve just changed a template or switched sending domains.
Best for: a fast pre-send gut check on a new template or domain.
3. GlockApps
GlockApps is widely considered the strongest option for repeatable, seed-based inbox placement testing across every major mailbox provider, plus concrete filter diagnostics on why a message landed in spam. Pricing ranges from roughly $79 to $559 a month depending on test volume and provider coverage. If you need to prove where your emails actually land, not just guess, this is the tool most operators reach for.
Best for: teams that need hard proof of inbox placement across Gmail, Outlook, and Yahoo.
4. Mailreach
Mailreach combines automated warmup with inbox placement testing and domain health monitoring in one dashboard, which makes it a reasonable one-stop option for teams that don’t want to stitch together three separate tools. It’s frequently named alongside GlockApps and Folderly as one of the top placement-testing platforms in 2026.
Best for: combining warmup and placement testing without managing separate subscriptions.
5. Warmy.io
Warmy exists mainly for teams running many individual mailboxes for outbound sending, gradually building sender reputation through simulated engagement before those inboxes go into real campaigns. Pricing is volume-based and typically gated behind a demo, with separate plans for B2B and B2C sending patterns. It pairs well with the kind of infrastructure a cold outreach team builds alongside dedicated email warmup tools when scaling past a handful of sending domains.
Best for: agencies and SDR teams warming up dozens of mailboxes at once.
6. Folderly
Folderly focuses on diagnosing why emails land in spam and then fixing the underlying authentication or content issues, rather than just reporting the problem. It’s positioned as an AI-assisted deliverability tool, bundling warmup, spam testing, and reputation monitoring into a single subscription. Teams that have already tried warmup alone and are still fighting placement issues tend to land here next.
Best for: diagnosing recurring spam-folder problems that warmup alone hasn’t fixed.
7. Lemwarm
Lemwarm, built by the Lemlist team, is a straightforward automated warmup tool that gradually increases sending volume and engagement signals on a new or recovering domain. It’s less of a full deliverability suite and more a focused warmup layer, which makes it a lighter-weight add-on if you already have placement testing and DMARC monitoring covered elsewhere.
Best for: a no-frills warmup add-on for teams already using Lemlist.
8. Mailgun Optimize
Mailgun Optimize starts at $49 a month and includes 2,500 email validations plus 25 inbox placement tests, with advanced reputation monitoring tiers starting at $99 a month. It’s a fit for teams that want deliverability tooling bundled with the sending infrastructure itself rather than bolted on as a separate vendor.
Best for: teams already sending through Mailgun who want validation and placement testing in the same bill.
9. EasyDMARC
EasyDMARC pricing starts at $35.99 a month for 100,000 emails across two domains, with a free plan covering 1,000 emails a month on a single domain. It parses DMARC aggregate reports into a readable dashboard so you can see who’s sending on your domain’s behalf and catch spoofing or misconfiguration before it tanks your reputation. Pair it with email verification tools that clean your list before send, since authentication and list hygiene solve different halves of the same reputation problem.
Best for: smaller teams that want accessible DMARC monitoring without enterprise pricing.
10. Valimail
Valimail specializes in DMARC authentication with a free monitoring tier and differentiates on fully automated DNS management for enforcement, along with FedRAMP certification and a Microsoft 365 partnership that matters for larger, more regulated organizations. It requires less manual configuration than EasyDMARC but is generally aimed at bigger teams with more complex sending infrastructure.
Best for: larger organizations that want DMARC enforcement automated rather than managed by hand.
11. Postmark DMARC Monitor
Postmark’s DMARC monitor is free for select email sources and IPs, with unlimited monitoring across all domains available for $14 a month, making it one of the cheapest ways to get real DMARC visibility. It’s a low-commitment starting point if you’re not yet ready to evaluate EasyDMARC or Valimail’s fuller feature sets.
Best for: budget teams that want basic DMARC visibility for under $15 a month.
12. MailerCheck
MailerCheck combines list verification with inbox placement testing and blacklist monitoring, aimed at teams that want deliverability checks built around list quality rather than warmup or authentication alone. It’s a reasonable middle ground for teams whose biggest deliverability risk is a stale or purchased list rather than a technical misconfiguration.
Best for: teams whose deliverability problems trace back to list quality more than infrastructure.
13. Amplemarket
Amplemarket bundles all seven components RevOps teams typically need: email warmup, inbox placement testing, domain health monitoring, SPF, DKIM, and DMARC monitoring, proactive spam checking, AI-powered mailbox selection, and dedicated IP pools. It’s the most complete single-vendor option on this list, which also means it’s overkill if you only need one or two pieces of the stack.
Best for: RevOps teams that want the entire deliverability stack under one login instead of stitching together five tools.
Building the stack that actually matters
Most RevOps teams don’t need all 13 of these running at once. A reasonable baseline is Google Postmaster Tools and a DMARC monitor like Postmark or EasyDMARC for free authentication visibility, GlockApps or Mailreach for periodic placement testing, and a warmup tool if you’re actively scaling sending volume on new domains. Add list verification only once you’ve ruled out authentication and reputation as the source of your problem, since a clean list sent from a misconfigured domain still lands in spam.