Best Email Deliverability Tools Compared
· 8 min read
Checks run by DNS only. Nothing is sent from or to your domain.
The best email deliverability tools cover four jobs: blacklist monitoring, authentication and DMARC reporting, mailbox provider reputation, and inbox placement testing. BlacklistMonitoring, MxToolbox, GlockApps, EmailGuard, EasyDMARC and Validity each lead in different jobs, so the right choice depends on which problem you have.
Most comparison lists rank tools by a score nobody can verify. This one does something more useful. It explains what each kind of deliverability tool actually measures, compares the main products on their public pages, and ends with a short guide to picking a setup that fits your sending. We make one of the tools in the table, so we have tried to describe the others the way their own pages do. Prices below are taken from public pricing pages at the time of writing. Prices and plans change often, so confirm on each vendor site before you buy.
What an email deliverability tool should do
Deliverability has several layers, and a problem in any one of them sends mail to spam. Before comparing products, it helps to know the layers, because most tools are strong in one or two and light in the rest.
Blacklist monitoring
DNS blacklists such as Spamhaus ZEN, Spamhaus DBL, Barracuda BRBL, SpamCop and UCEPROTECT list IPs and domains that their operators link to spam. Receivers query them for every incoming message. A good tool checks your IPs and domains on many lists on a schedule and alerts you when a listing appears. The key questions are how many lists, how often, and how many domains you can watch before the price jumps. For background, see what an IP blacklist is.
Authentication and DMARC reporting
SPF, DKIM and DMARC prove that mail claiming to be from your domain really is. Since February 2024 Google and Yahoo require bulk senders to have all three, with DMARC aligned to the From domain, and Microsoft added similar rules for high volume senders to Outlook.com in May 2025. A tool here should check your records (including the 10 DNS lookup limit for SPF) and, more importantly, read your DMARC aggregate reports so you can see every service that sends as you.
Reputation at mailbox providers
Gmail and Outlook keep their own reputation for your domain and IPs. You see it through Google Postmaster Tools and Microsoft SNDS, which are free. The most important number is the user-reported spam rate at Gmail, which must stay below 0.3 percent and ideally below 0.1 percent. Some tools pull these signals into one view and alert you when they move.
Inbox placement testing
Your ESP reports a message as delivered when the receiving server accepts it. Placement tests show where it went next, inbox or spam, by sending to seed mailboxes at Gmail, Outlook, Yahoo and others. This is the only direct evidence of spam folder problems, which is why placement-focused tools exist.
Alerts and reporting
A tool that finds a problem is only useful if someone sees it in time. Look at alert channels (email, Slack, Teams, webhooks), how fast checks repeat, and whether you can share results with clients or other teams.
Email deliverability tools compared
The table summarizes each tool as described on its own public pages. It is a starting point, not a verdict.
| Tool | Main strength | Blacklist monitoring | Best fit | Price from |
|---|---|---|---|---|
| BlacklistMonitoring | All layers in one panel: blacklists, SPF, DKIM, DMARC reports, reputation, placement | 109 lists, every 60, 15 or 5 minutes by plan | Companies and agencies with many domains and IPs | $49/mo, or $24/mo billed yearly |
| MxToolbox | DNS lookups and diagnostics | Yes, both paid plans capped at 5 domains | IT teams who want a familiar DNS toolkit | Free weekly monitoring for 1 domain, paid $129 or $399/mo |
| GlockApps | Inbox placement testing | Through IP reputation monitors only | Marketers who mainly need placement tests | $59 to $129/mo |
| EmailGuard | Cold email tooling | Weekly automated checks | Cold email senders | $49 to $199/mo |
| EasyDMARC | DMARC deployment and reporting | Not the focus, deliverability features sold through sales | Teams whose main goal is reaching p=reject | See vendor site |
| Validity | Enterprise deliverability and placement | Part of a larger suite | Large senders with an enterprise budget | Custom quote through sales |
| HetrixTools | Low-cost RBL monitoring | Yes, IP and domain blacklists | Hosting providers who only need list checks | See vendor site |
Two free tools belong in every setup regardless of what you buy: Google Postmaster Tools and Microsoft SNDS. They are the only first-party view of how Gmail and Outlook see you.
The tools in more detail
BlacklistMonitoring
This is our product, so read this section with that in mind. BlacklistMonitoring is built as one panel for every domain and IP a company sends from. It checks 109 DNS blacklists, runs SPF, DKIM, DMARC, MX, PTR, BIMI, MTA-STS and TLS-RPT checks, ingests DMARC aggregate reports into a readable dashboard with sender source discovery, connects Google Postmaster Tools, Microsoft SNDS and Yahoo signals, alerts on spam rate at 0.1 and 0.3 percent, and runs inbox placement tests from the Business plan. Each finding is written as a plain sentence with the fix.
Plans start at $49 a month (10 domains and IPs, hourly checks) and go through Business at $149, Agency at $499 with client workspaces and white label reports, and Scale at $1,499 with CIDR ranges and a REST API. Yearly billing halves each price. There is no free plan, but there is a free one-off check on the site. The weak spot compared with a dedicated placement vendor is depth of seed testing: our tests are included per plan (50, 300 or 1,500 a month) rather than sold as the main product. See email deliverability monitoring for the full feature list.
MxToolbox
MxToolbox is the DNS toolkit most IT people already know. Its free lookups for MX, SPF, DKIM and blacklists are quick and reliable, and its paid plans add monitoring. Its public pricing lists a free plan with weekly blacklist monitoring for one domain, then Delivery Center at $129 a month and Delivery Center Plus at $399 a month, both for 5 domains. That suits a company with a few domains. It gets expensive for agencies or anyone with dozens of sending domains. Our MxToolbox pricing breakdown works out the cost per domain, and the MxToolbox alternative page compares the two products feature by feature.
GlockApps
GlockApps is known for inbox placement testing, with seed lists across many providers and spam filter results per test. It also offers DMARC analytics. Blacklist coverage comes through IP reputation monitors, which suits senders on dedicated IPs more than those who mainly need domain list coverage. Plans run from $59 to $129 a month. If your main question is "inbox or spam, per provider, per campaign", GlockApps is a strong choice.
EmailGuard
EmailGuard is aimed at cold email senders, with tools for inbox testing, content checks and domain management. Its automated blacklist checks run weekly, which is fine for spotting long listings and slow for catching a listing during the same sending week. Plans run from $49 to $199 a month. If you run cold outreach, our guide to cold email domain rotation covers how monitoring fits into that workflow.
EasyDMARC
EasyDMARC focuses on DMARC: setting up records, reading aggregate reports and moving domains safely to p=reject. It does that well. Wider deliverability features sit behind sales conversations rather than self-serve plans. Choose it if anti-spoofing is your main project and you have other tools for blacklists and placement.
Validity
Validity sells enterprise deliverability products (Everest is the best known) with inbox placement, reputation and sender certification. It is aimed at large senders and sold through sales, with custom pricing. Large retailers and publishers with a deliverability team often use it. Smaller teams usually find it more than they need.
HetrixTools
HetrixTools is a low-cost blacklist and uptime monitor popular with hosting providers. It checks IPs and domains against RBLs and alerts you when one is listed. It does not handle DMARC reports, mailbox provider reputation or placement, so it covers one layer only.
How to choose a deliverability tool
Start from the problem, not the feature list. These questions narrow the choice quickly:
- How many domains and IPs do you send from? One or two domains fit almost any tool. Twenty or more, common for agencies and cold email teams, rule out tools that price per monitor or cap domains low.
- How fast do you need to know? Weekly checks work for slow-moving reputation. Hourly or faster matters if a listing during a campaign costs real money.
- Is your main risk spam folder placement or blocking? Placement problems need seed tests and Postmaster data. Blocking problems need blacklist and authentication monitoring.
- Do you need DMARC reports read for you? If you have not reached
p=rejectyet, report analysis is not optional. See our guide on how to read a DMARC aggregate report to see what is involved. - Do you report to clients? Agencies need separate client workspaces and branded reports, or they end up building them by hand every month.
Suggested setups by sender type
| Sender | What matters most | A sensible setup |
|---|---|---|
| Small business, one domain | Authentication and blacklist alerts | Free Postmaster Tools plus an entry monitoring plan |
| Ecommerce store | Spam rate during peaks, app senders in DMARC | Monitoring with spam rate alerts, DMARC reports and occasional placement tests |
| SaaS product | Sign-up and reset emails reaching the inbox | Monitoring with webhook alerts into on-call, separate subdomains for marketing |
| Cold email agency | Many domains, fast listing alerts | Monitoring at short intervals with bulk import, plus placement tests per domain |
| Email marketing agency | Client separation and reporting | Client workspaces and white label deliverability reports |
| Large publisher or retailer | Placement at scale, dedicated IPs | Monitoring with CIDR ranges and SNDS, possibly an enterprise placement suite |
Free tools worth using first
Before paying for anything, set up the free basics. Many deliverability problems are visible in them.
- Google Postmaster Tools. Domain reputation, spam rate and authentication results at Gmail. Verify your domain once and data appears when you send enough volume.
- Microsoft SNDS. Complaint rates and trap hits for your IPs at Outlook.com, useful for dedicated IPs.
- A one-off check. Our free email deliverability test looks at SPF, DKIM, DMARC, MX, PTR and blacklist status for a domain, IP or email address in one run, with no account needed.
- Your ESP bounce logs. Bounce messages often name the blacklist or policy that blocked you.
Free tools tell you where you stand today. Paid tools earn their price by watching continuously, keeping history and alerting the right person when something changes. If a missed listing or a spam folder week costs more than a monthly plan, monitoring pays for itself.
Common mistakes when buying
- Buying placement tests to fix an authentication problem. A test will tell you mail lands in spam. It will not tell you SPF is over 10 lookups. Check DNS first.
- Counting lists instead of checking which lists. Coverage of Spamhaus, Barracuda, SpamCop and the URIBL and SURBL domain lists matters more than a large total of obscure lists.
- Ignoring per-domain pricing. A cheap entry plan can turn expensive once every secondary domain counts against a small domain cap.
- Setting up DMARC and never reading the reports. A record at
p=nonewith no one reading reports protects nothing. - Relying on open rates. Privacy features that preload images make opens a weak deliverability signal. Use spam rate, placement and reply or click data instead.
Whichever tool you pick, the goal is the same: know about a problem before your customers or clients do. Compare plans on our pricing page if an all-in-one setup fits your sending.