Email deliverability tools test whether messages reach the inbox, warm up new sending mailboxes and watch the signals mailbox providers hold against a sender.
This guide ranks twelve products on setup effort, the bill once testing, warm-up and monitoring are all needed, how reports leave, and whether one company can run the work without a partner.
Vendors can pay for more visibility on this website, for example a higher place in a ranking or more room on a page. Commercial relationships can also affect which products we feature and how prominently. Every vendor link is marked the same, whatever the arrangement behind it. How that works.
In short
What email deliverability tools software does
Email deliverability tools check authentication records, run spam and inbox-placement tests, warm up new mailboxes and monitor blocklists and sender reputation, so senders can see why mail lands in spam.
Our order comes from five tests, taken in turn: effort to set up, what you really pay, what happens to your data on the way out, how locked in you are, and the intended customer. One rule overrides the order: smaller vendors take the first three places when the category offers them, and the best-known brands start at four. The reasoning behind the five tests, and behind having no score out of ten, is set out on the how we work page.
Free plan with two test credits; three paid monthly tiers published, cheaper billed annually; DMARC overage charged per message block; custom plan on request
Yes
Teams wanting placement tests and DMARC reports from one supplier
Buyers who need mailbox warm-up included in the plan
Mailbox warm-up and spam testing sold together, priced per mailbox
Ranked #1 of 12 in Best Email Deliverability Tools in 2026.
Published pricingEurope
MailReach packages two jobs: a warm-up that runs on each mailbox and a spam tester that sends to seed addresses. The calculator on the pricing page shows the combined bill before signup, and the warm-up plan includes at least 20 test credits.
It also lists reputation tracking and blacklist, SPF, DKIM and DMARC checks. Pay-as-you-go testing exists for teams that do not want warm-up. Expect the total to scale mailbox by mailbox.
What stands out
Warm-up and testing
Per mailbox
Seed-list spam tests
Where it costs you
Cost rises with every mailbox you warm, so large outbound teams must price a full fleet before committing.
The warm-up plan lists up to 100 emails a day, which caps volume per mailbox.
Right for
Teams warming a handful of sending mailboxes who also want spam tests
Wrong for
Fleets of hundreds of mailboxes on a tight budget
FrancePer mailbox per month plus spam-test credits, calculator published, lower with annual billing; custom pricing from 100 mailboxes
Seed-list inbox testing, DMARC reports and monitors under one subscription
Ranked #2 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingNorth America
GlockApps tests with a seed email list and shows how mailbox providers treat each message. The same subscription carries DMARC analytics, uptime monitors, IP reputation monitors and postmaster tool seats, with higher tiers raising each count.
A free plan lets you try two tests. Its own page lists no warm-up product in the plans, so cold-email teams pair it with a warm-up tool. Metered DMARC rates fall as the tier rises.
What stands out
Seed-list testing
DMARC analytics
Uptime monitors
Where it costs you
Test credits are limited on every tier, starting at two on the free plan.
Extra DMARC messages are metered in blocks, at a lower rate on bigger tiers.
Right for
Teams wanting placement tests and DMARC reports from one supplier
Wrong for
Buyers who need mailbox warm-up included in the plan
United StatesFree plan with two test credits; three paid monthly tiers published, cheaper billed annually; DMARC overage charged per message block; custom plan on request
Warm-up network billed per inbox, with a seven-day trial
Ranked #3 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingEurope
Warmup Inbox bills per inbox per month on Basic, Pro and Max, with daily warm-up messages of 75, 250 and 1,000. The homepage offers a seven-day trial and a free plan without a trial clock.
Pro adds scheduled warm-up and specific ESP warm-up, and Max adds premium support and a technical setup check. From 51 inboxes pricing moves to a call with the company. A placement test is offered as a free tool.
What stands out
Per inbox
Language warm-up
Built-in sequences
Where it costs you
Basic leaves out custom templates, topic choice and language warm-up; those begin on Pro.
Placement figures on the site are internal benchmarks, not independent tests.
Right for
Outbound teams wanting per-inbox warm-up with a trial and a free plan
Wrong for
Teams needing placement testing and DMARC reports in one tool
SlovakiaFree plan and 7-day trial; Basic, Pro and Max priced per inbox per month, published; 51 inboxes and up quoted
Send one email to a test address and read the report
Ranked #4 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingNorth America
Mail goes to a generated address, and a report comes back, with no account needed for occasional use. Three tests per 24 hours cost nothing; beyond that, monthly subscriptions and one-off packs are listed, and account holders get an API, 30-day history and no ads.
It is a fast first check for a new domain, but it does not warm mailboxes or watch reputation over time.
What stands out
Single-message test
SpamAssassin
Pay per test
Where it costs you
It scores against one default SpamAssassin install, not against Gmail or Outlook filters.
Free results are deleted after seven days and anyone with the address can open them.
Right for
Anyone checking one email's authentication and content before a send
Wrong for
Ongoing monitoring or testing placement across mailbox providers
United StatesFree tier of three tests per 24 hours; monthly test subscriptions and one-off test packs published; API for account holders
Estonian warm-up service with plans sized by inbox count
Ranked #5 of 12 in Best Email Deliverability Tools in 2026.
Published pricingEurope
Warmbox lists the same features on every plan, so Solo, Start-up and Growth differ only in inbox count, daily volume and team seats.
Inboxes connect as Gmail via OAuth, Microsoft 365, or any other mailbox through SMTP, and warm-up can follow a growth, flat or random schedule. A live checker covers DNS and blocklists. The company is an Estonian OÜ, and billing is lower on the yearly toggle.
What stands out
Inbox bundles
SMTP inboxes
Flat or random ramp
Where it costs you
Daily ceilings are 50, 250 and 500 emails on the three standard plans.
Larger fleets than six inboxes need a custom Team plan, so pricing is not visible.
Right for
Small senders warming one to six inboxes on any SMTP provider
Wrong for
Agencies managing dozens of inboxes who need published volume pricing
EstoniaSolo, Start-up and Growth plans for one, three or six inboxes, prices published, lower billed yearly; Team plan custom
Suite of deliverability products, each with its own pricing
Ranked #6 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingNorth America
Folderly now presents a suite rather than one app. Inbox Insights tests placement, IPs and DNS, with two tests a month on its free tier; Pulse tracks placement and alerts; DMARC Pilot reads aggregate reports; Lens inspects public domain and IP signals.
Folderly itself is the sender-reputation product billed per mailbox. The pages note that access differs per product, so confirm which pieces you need before you buy.
What stands out
Product suite
Inbox Insights
DMARC Pilot
Where it costs you
Products are split, so a full workflow needs several subscriptions.
Core Folderly is billed per mailbox, so large fleets add cost quickly.
Right for
Teams that want placement tests first and warm-up later, in one brand
Wrong for
Buyers wanting a single price for every function
United StatesFolderly core priced per mailbox per month, published; Inbox Insights has a free tier of two tests a month; demo for other products
Warm-up included in lemlist plans, or bought alone per email account
Ranked #7 of 12 in Best Email Deliverability Tools in 2026.
Published pricingEurope
lemwarm connects Gmail and Outlook in one click and also lists Zoho, FastMail and Proton. It warms through a network of 20,000+ domains and tracks a deliverability score with spam-risk alerts and SPF, DKIM, DMARC and MX checks.
Essential suits solo senders and Smart suits teams. No standalone trial is mentioned, while any lemlist plan includes it. Plan on roughly six weeks from first warm-up to live campaigns.
What stands out
Per email account
Gmail and Outlook
Deliverability score
Where it costs you
Reputation falls if warm-up is switched off, so the charge never ends.
Personalised warm-up and custom alerts require the Smart tier.
Right for
lemlist users, or small teams warming a few Gmail and Outlook accounts
Wrong for
Teams wanting spam tests or DMARC reports from the same tool
FranceTwo tiers priced per email account per month, published, lower billed yearly; included in every lemlist plan; Custom tier by contact
Blocklist and DNS lookups, with paid monitoring and delivery reports
Ranked #8 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingElsewhere
MXToolbox started as lookups and is sold today as monitoring. The free plan has weekly blocklist monitoring for one domain.
Delivery Center and Delivery Center Plus add mailflow monitoring, DMARC delivery reports, inbox placement analyses, BIMI management and impersonation protection, and the larger plan adds SPF flattening. The pages do not state where the company is based, and nothing there describes warming a mailbox.
What stands out
Blocklist monitoring
DMARC reports
Inbox placement
Where it costs you
Inbox placement analysis is only on the two paid plans.
Free covers one domain only.
Right for
Admins who need blocklist, DNS and authentication checks plus alerts
Wrong for
Cold-email senders who need warm-up or spam-content scoring
Not stated by the vendorFree plan with weekly blocklist monitoring for one domain; two paid monthly plans published
Google dashboards for mail sent to Gmail: spam rate and reputation
Ranked #9 of 12 in Best Email Deliverability Tools in 2026.
Free tierPublished pricingNorth America
Postmaster Tools gives the sender four dashboard areas: spam rate, reputation, message authentication and delivery errors.
You add the domain used for SPF or DKIM and prove ownership through DNS, and access can be shared with other Google accounts for verified domains. The help page names no price. It diagnoses Gmail only, so most teams pair it with a testing tool for other providers.
What stands out
Gmail only
Spam rate
Domain verification
Where it costs you
It only covers mail sent to Gmail addresses.
Dashboards show nothing when daily sending volume is low.
Right for
Bulk senders who need Gmail's own view of spam rate and reputation
Wrong for
Low-volume senders or anyone needing Outlook and Yahoo visibility
United StatesFree to use with a Google or Workspace account; the help page names no paid plan
Optimize line adds placement tests and blocklist monitoring to Mailgun
Ranked #10 of 12 in Best Email Deliverability Tools in 2026.
Published pricingNorth America
Mailgun Optimize is the checking layer of a sender that now sits inside Sinch Email, and it runs alongside any email service provider through the API or dashboard. Pilot costs $49 a month and Starter $99, both with the first month free.
Starter adds spam trap monitoring, blocklist monitoring and links to Google Postmaster Tools and Microsoft SNDS. Enterprise buyers get a quote. For this market it is a metered testing product, not a warm-up service.
What stands out
Inbox placement tests
Postmaster link
Sinch Email
Where it costs you
Placement tests are capped at 25 on Pilot and 50 on Starter, with extra tests billed from $0.75 each.
Email previews sit in the separate Inspect product, so rendering checks cost extra.
Spam trap and blocklist monitoring on Starter covers a single domain and a single IP.
Right for
Teams that already send through another provider and want placement tests and blocklist alerts added on top
Wrong for
Agencies watching many client domains, since the entry plan watches one domain and one IP
United StatesPilot and Starter plans published monthly with the first month free; enterprise suite quoted; works alongside other senders
Cold-email sender where warm-up comes bundled into outreach plans
Ranked #11 of 12 in Best Email Deliverability Tools in 2026.
Published pricingNorth America
Instantly ranks low among deliverability tools because it is a sending platform first. Unlimited email accounts and warm-up start with the Growth outreach plan, while the Scale bundle at $194 a month adds advanced deliverability features.
Light Speed and Enterprise include private servers and IP blocks, and Enterprise adds a Private Deliverability Network. Limits count monthly emails and contacts. Buyers shopping for a dedicated warm-up or testing tool should price what they would not use.
What stands out
Outreach platform
Unlimited warm-up
Dedicated IP blocks
Where it costs you
Warm-up only comes with outreach plans from Growth at $47 a month, so a team with no cold campaigns still pays for sending.
Spam testing and monitoring are not offered as a standalone product in the sources checked.
The pricing page shows inconsistent prices in places and does not state a trial length.
Right for
Cold-email teams that want warm-up included in the sending tool and are happy to run campaigns there
Wrong for
Teams that only want to test placement or watch blocklists without moving their outreach
United StatesMonthly or yearly billing, prices published; outreach, lead and credit plans sold separately; Enterprise and VIP custom
Email QA and deliverability checks, now inside Validity Engage
Ranked #12 of 12 in Best Email Deliverability Tools in 2026.
Pricing on requestNorth America
Litmus pairs rendering previews across 100+ clients with deliverability checks that show which providers send mail to spam and track SPF, DKIM and DMARC results.
The product now sits inside Validity Engage, and Validity says Engage is priced on the features a team needs. Demos run through the sales form. It is a fit for design and QA workflows, and it contains no warm-up product on the pages checked.
What stands out
Part of Validity
Client previews
Placement by provider
Where it costs you
No price or trial is published, so cost is known only after a sales conversation.
Order forms under Validity's terms run 12 months and renew automatically.
Right for
Larger email teams that need previews and placement under one contract
Wrong for
Small senders wanting a public price list and card checkout
United StatesQuoted per organisation; the Get started button leads to sales and no trial is stated
Email deliverability tools check authentication records, run spam and inbox-placement tests, warm up new mailboxes and monitor blocklists and sender reputation, so senders can see why mail lands in spam. The differences that matter are rarely in the feature list, so this is the order we would work through them.
01
Start with pricing transparency
Prices are public at 11 products (MailReach, GlockApps, Warmup Inbox, Mail-Tester, Warmbox, Folderly, lemwarm, MXToolbox, Google Postmaster Tools, Mailgun, Instantly) and on request at the remaining 1, so budget time for quotes if your favourite is in that second group.
02
Weigh the vendor's home jurisdiction
Check the vendor's home market (North America 7, Europe 4, Elsewhere 1), because that is where subpoenas and data requests arrive first, whatever region holds your files.
Testing inbox placement with GlockApps, MailReach or Mail-Tester
Three tools in this ranking promise a test, and they measure different things. GlockApps and MailReach send to seed lists and report where messages land by provider; Mail-Tester runs one message through a default SpamAssassin install and reports on the message, server and sending IP. A SpamAssassin score will not tell you whether Gmail puts the message in Promotions.
Credits are the second trap: GlockApps starts at two on its free plan, and MailReach bundles a minimum of 20 with warm-up. Decide how many campaigns you will test each month before comparing tiers, because an active team can burn through a small allowance in a week. Mailgun Optimize and MXToolbox also sell placement tests, but only on paid plans.
Ask whether the test uses a seed list or a single filter
Count monthly tests against the credits in each tier
Check how long results stay available and who can open them
Warming mailboxes with Warmup Inbox, Warmbox and lemwarm
Warm-up tools bill by mailbox, so the cost is a multiplication, not a licence. Warmup Inbox charges per inbox on three tiers with 75, 250 or 1,000 daily messages; Warmbox sells bundles of one, three or six inboxes capped at 50, 250 and 500 a day; lemwarm charges per email account and lists a month of warm-up before the two-week run-up to real campaigns.
lemwarm adds that reputation drops once warm-up stops, so the charge repeats every month. Multiply price by every sending mailbox, then add the months you will keep them warm. Which tier you need depends on the daily volume per mailbox, not on your headcount, and features such as custom templates may sit on a higher tier than the one advertised first. Ask each vendor what is included at the entry price.
Multiply the per-mailbox price by every sending mailbox
Compare the daily message ceiling with your real sending volume
Check which features, such as custom templates, need the higher tier
Monitoring with Google Postmaster Tools, MXToolbox and Folderly
Once mail is flowing, the question changes from testing to watching. Google Postmaster Tools gives Gmail's own view of spam rate, reputation and authentication, costs nothing and covers only Gmail recipients, with dashboards empty when volume is low. MXToolbox adds blocklist monitoring on its free plan for a domain, with placement analyses and DMARC delivery reports on the paid ones.
Folderly splits monitoring into Pulse for alerts and DMARC Pilot for aggregate reports. A small sender may need only Postmaster Tools plus a blocklist monitor, while an agency needs several domains and alerts to a shared channel. Match domain count and alert routes to the tier before you buy, and check that nothing important sits behind a higher plan.
Confirm how many domains each tier monitors
Check whether the tool covers more than Gmail
Find out where alerts are sent and how often checks run
Bundled deliverability in Instantly, Mailgun and Litmus
Three entries here sell deliverability inside something larger. Instantly folds warm-up into outreach plans measured in emails and contacts, so a buyer who wants only testing pays for a sending platform. Mailgun Optimize can be bought without Mailgun's sending service and works with other providers, but email previews sit in the separate Inspect product.
Litmus has joined Validity Engage, lists no price and routes buyers to sales; Validity's terms describe annual order forms that roll over unless cancelled two months ahead. Ask for the exit terms and the export of reports before signing, and write down which features you would never use, since those are the part of the price you are paying for convenience.
Ask which features you would pay for but not use
Read the renewal and notice terms before signing
Check whether test history and reports can be exported
What goes wrong most often when buying email deliverability tools software
Buying a warm-up tool for a domain that has no SPF, DKIM or DMARC record set up first.
Treating a single Mail-Tester result as proof that Gmail and Outlook will place the message in the inbox.
Pricing warm-up for one mailbox and forgetting it is billed again for every extra sending address.
Switching warm-up off once campaigns start, when lemwarm says reputation drops once it stops.
07
Frequently asked questions
6 answers
What is the best email deliverability tools in 2026?
MailReach leads our ranking of 12. MailReach is published by THE BRAIN COMPANY, a simplified joint stock company in Paris.
The pricing page is a calculator: every mailbox and every block of test credits changes the total, and the warm-up plan always carries at least 20 test credits. That bundle keeps setup short. The cost climbs with each mailbox, and the warm-up plan lists a ceiling of 100 emails a day.
Which email deliverability tools publish their pricing?
Published pricing exists for 11 products on this page:
MailReach: Per mailbox per month plus spam-test credits, calculator published, lower with annual billing; custom pricing from 100 mailboxes.
GlockApps: Free plan with two test credits; three paid monthly tiers published, cheaper billed annually; DMARC overage charged per message block; custom plan on request.
Warmup Inbox: Free plan and 7-day trial; Basic, Pro and Max priced per inbox per month, published; 51 inboxes and up quoted.
Mail-Tester: Free tier of three tests per 24 hours; monthly test subscriptions and one-off test packs published; API for account holders.
Warmbox: Solo, Start-up and Growth plans for one, three or six inboxes, prices published, lower billed yearly; Team plan custom.
Folderly: Folderly core priced per mailbox per month, published; Inbox Insights has a free tier of two tests a month; demo for other products.
lemwarm: Two tiers priced per email account per month, published, lower billed yearly; included in every lemlist plan; Custom tier by contact.
MXToolbox: Free plan with weekly blocklist monitoring for one domain; two paid monthly plans published.
Google Postmaster Tools: Free to use with a Google or Workspace account; the help page names no paid plan.
Mailgun: Pilot and Starter plans published monthly with the first month free; enterprise suite quoted; works alongside other senders.
Instantly: Monthly or yearly billing, prices published; outreach, lead and credit plans sold separately; Enterprise and VIP custom.
The remaining 1 sell by quote.
Is there a free email deliverability tool?
GlockApps, Warmup Inbox, Mail-Tester, Folderly, MXToolbox, Google Postmaster Tools come with a no-cost entry point, a free plan or a self-hosted edition.
Where are these email deliverability tool vendors established?
In 5 countries across 3 regions: North America 7, Europe 4, Elsewhere 1.
MailReach: France.
GlockApps: United States.
Warmup Inbox: Slovakia.
Mail-Tester: United States.
Warmbox: Estonia.
Folderly: United States.
lemwarm: France.
MXToolbox: Not stated by the vendor.
Google Postmaster Tools: United States.
Mailgun: United States.
Instantly: United States.
Litmus: United States.
What should you use instead of MailReach?
GlockApps and Warmup Inbox are the next two on this page. GlockApps is for teams wanting placement tests and DMARC reports from one supplier; Warmup Inbox is for Outbound teams wanting per-inbox warm-up with a trial and a free plan.
Who should not buy MailReach?
Fleets of hundreds of mailboxes on a tight budget. Cost rises with every mailbox you warm, so large outbound teams must price a full fleet before committing..
We rank 12 email deliverability tools products on this page. If we missed one, its maker can write to us about its purpose and customers. We pick what gets added; the terms of a listing are set out under software advice.
