The 8 Best Email Deliverability and Warmup Tools (2026)

Quick answer: which deliverability tool fits you

• You want warmup, placement tests, DMARC monitoring and blacklist alerts from one vendor: Warmy, from $49 a month with a 7-day free trial and no card.
• You want the cheapest dedicated warmup per inbox and a spam test after every change: MailReach, which showed $19.50 per mailbox a month with 20 spam test credits included when we checked.
• You already send with Instantly: use its built-in warmup. Unlimited warmup is listed on the $47 Growth plan, so a separate tool only makes sense if you're fixing a problem.
• You already pay for lemlist: lemwarm is included in every lemlist plan. On its own it's $29 per inbox a month.
• You need to test where emails land and watch DMARC, not warm inboxes: GlockApps, from $59 a month for 360 spam test credits, with a free plan of 2 tests.
• You have a deliverability problem you can't diagnose and want people on it: Folderly ($96 per mailbox a month, billed yearly) or Mailwarm, which includes expert calls on every plan.
• You want inboxes, warmup and a money-back placement promise in one bill: EmailWarmup.com, $29 per mailbox a month, but read the guarantee terms first.

If you'd rather not manage inboxes and warmup yourself at all, skip to the section on when to hire an agency, or book a campaign plan call and we'll tell you honestly whether a tool or a service fits your team.

How we ranked them

We send cold email for B2B companies every day across many secondary domains, so warmup and inbox placement are things we check every week, not once at setup. Each tool was scored on six things:

• Pricing transparency: does the vendor publish what one inbox, or one test, costs?
• What it does best: warming inboxes, testing placement, monitoring authentication, or hands-on fixing.
• Deliverability features: seed list placement tests, SPF, DKIM and DMARC checks, blacklist monitoring and Google Postmaster data.
• Integrations: which mailbox providers and sending tools it connects to, and whether there's an API.
• Ease of setup: free trial terms and how fast you can connect a first inbox.
• Reviews: G2 star rating with the review count. Several tools here have fewer than 50 reviews, and we say so.

Every price below comes from the vendor's own pricing page, checked in November 2026. G2 blocked our checker, so ratings and counts come from G2's own listing and comparison pages as indexed that month; counts move every week, so treat them as a snapshot. Where a vendor's page contradicts itself, we say so.

Email deliverability and warmup tools compared

Starting price is the cheapest paid plan billed monthly unless noted. Per-mailbox tools charge that price for every inbox you warm.

The 8 best email deliverability and warmup tools

1. Warmy: the most complete standalone deliverability suite

Warmy warms mailboxes and domains, then tells you where your mail actually lands. Its pricing page lists a 500K+ US seed list that rotates monthly, placement test credits, a deliverability tester that checks placement, authentication and blacklists, DMARC monitoring, a reputation tracker with blacklist alerts, Google Postmaster data, email verification, a template checker and full API access. It warms both B2B mail (Google Workspace, Microsoft 365) and consumer inboxes (Gmail, Yahoo, Outlook).

Pricing, from Warmy pricing: three plans, B2B sender, B2C sender and Custom, each starting at $49 a month. The page says you pay for the warmup volume you need but doesn't publish per-mailbox or per-day figures, and the monthly placement test allowance is "to be confirmed" with Warmy's team. Custom adds a dedicated success manager. The trial is 7 days, needs no credit card, and lets you test any package.

Best for: teams that want one login for warmup, testing and monitoring, and anyone sending both B2B and consumer email. The homepage also links a long list of free tools (SPF, DKIM and DMARC checkers and generators, a blacklist checker, a warmup volume calculator), which are worth using even if you never buy.

Watch-outs: "from $49" is all you get without talking to Warmy. If you plan to warm 30 inboxes, ask for a written quote before the trial ends. The open and click lifts on the homepage (2.3x opens, 3x clicks) are Warmy's own numbers and the page doesn't say how they were measured.

G2: 4.8 out of 5 from about 525 reviews on Warmy's G2 seller page. Warmy's own site shows 4.9.

2. MailReach: low per-inbox warmup with spam tests built in

MailReach does two jobs: it warms each connected mailbox, and it runs spam tests that show inbox, spam or promotions placement by provider. Its All-In-One plan lists a warmup algorithm that sends up to 100 emails a day, warmup across Google, Outlook and other providers, a reputation dashboard and domain health checks for blacklists, SPF, DKIM and DMARC.

Pricing, from MailReach pricing: the All-In-One monthly plan showed $19.50 per mailbox a month, always including at least 20 spam test credits (1 credit is 1 placement test). Annual billing saves 20%, and there's also a pay-as-you-go option for spam tests. The calculator totals on the page didn't add up when we checked, so price your exact inbox count in checkout. Third-party write-ups report $25 per mailbox for 5 or fewer inboxes and $19.50 from 6; we couldn't confirm that tier break on the live page. No free trial is mentioned on the pricing page.

Best for: cold email teams warming 10 to 50 inboxes on a separate tool from their sender, who want to run a placement test after every copy or domain change.

Watch-outs: per-mailbox pricing adds up. At $19.50, 15 inboxes are $292.50 a month, while Instantly Growth includes unlimited warmup for $47. MailReach recommends at least 14 days of warmup before any campaign, which matches our experience. With 44 G2 reviews, the outside evidence is thin.

G2: 4.7 out of 5 from 44 reviews on MailReach on G2.

3. Instantly: warmup bundled with the sender most teams already use

Instantly isn't a deliverability tool first. It's a cold email sender, and warmup comes with it. If that's what you send from, its warmup is the cheapest option on this list per inbox, because you don't pay per inbox at all.

Pricing, from Instantly pricing: Outreach Growth is $47 a month ($37.60 billed yearly) and Hypergrowth is $97 ($77.60 yearly); both list unlimited email warmup. Light Speed is $358 ($286.30 yearly) and assigns dedicated server and IP blocks. Enterprise is custom and adds a Private Deliverability Network. The page says no credit card is needed to start but doesn't give a trial length.

Best for: any team already sending with Instantly. Connect every inbox, let warmup run for two to three weeks, and only add a standalone tool if placement tests show a problem.

Watch-outs: the pricing page doesn't list placement testing as a feature, so you'll still want a separate test (GlockApps, MailReach or Warmy's free tester) to check where you land. The bundles view on the same page showed Hypergrowth at $358 in one place and $97 in another when we checked, so confirm in checkout.

G2: 4.8 out of 5 from 4,163 reviews on Instantly on G2. That rating covers the whole product, not warmup alone.

4. lemwarm: simple per-inbox warmup, free with lemlist

lemwarm is the warmup tool from lemlist. It sends human-style warmup emails across a network of 20k+ healthy domains, checks your technical setup and sends deliverability reports. The higher plan warms your real email templates and tailors the network to your industry.

Pricing, from lemwarm pricing: Essential is $29 per email address a month, or $24 shown with the yearly discount. Smart is $49, or $40 yearly, and adds personalized warmup emails, warmup of your real templates and custom alerts. Custom is for teams with more than 10 users. Billing can be monthly, quarterly (save 10%) or yearly (save 20%). The page states that "Every lemlist plan includes lemwarm." It doesn't list trial terms or a daily volume.

Best for: lemlist customers (it's already in your plan) and solo founders warming one or two inboxes who want something simple.

Watch-outs: at $29 per inbox, 15 inboxes cost $435 a month, about $140 more than MailReach for the same count and without spam test credits. There's no seed list placement test listed on the pricing page.

G2: we found no separate lemwarm listing. lemlist, which includes it, has 4.6 out of 5 from 2,570 reviews on lemlist on G2.

5. GlockApps: placement testing and DMARC monitoring, no warmup

GlockApps is a testing and monitoring tool. You send a campaign to its seed list and see inbox, spam or missing placement by provider, and it adds a DMARC analyzer, uptime monitors and IP reputation monitors. It doesn't warm inboxes; its pricing page doesn't mention warmup at all.

Pricing, from GlockApps pricing: Free is $0 with 2 spam test credits, 10,000 DMARC messages and 1 IP reputation monitor. Essential is $59 a month with 360 spam test credits, 600,000 DMARC messages and 10 IP monitors. Growth is $99 with 1,080 credits, 1.2 million DMARC messages and 5 users. Enterprise is $129 with 1,800 credits, 12 million DMARC messages and 10 users. All plans cover unlimited DMARC domains. The annual toggle says "Save 30%," but the yearly totals shown ($708, $1,188, $1,548) are exactly 12 times the monthly price, so check the discount in checkout.

Best for: teams that already warm inboxes inside their sender and need an independent check before launching, plus anyone sending marketing or transactional mail who needs DMARC reports read for them.

Watch-outs: you'll need a warmup tool alongside it. One G2 reviewer reported a large price increase after setup, so lock in your plan terms in writing.

G2: 4.1 to 4.2 out of 5 from 26 to 27 reviews on GlockApps on G2, depending on which G2 page you read. Capterra shows 4.8 from 40.

6. Folderly: hands-on deliverability fixing at a premium

Folderly finds technical and content problems that push mail to spam, monitors placement and gives specific fixes. The company also sells Inbox Insights (pre-send placement, IP and DNS checks) and Pulse (placement tracking with alerts by email, Slack and SMS).

Pricing, from Folderly pricing: Folderly itself shows only one price, $96 per mailbox a month on yearly billing, with a demo to start. Inbox Insights has a free plan with 2 tests a month and a paid plan at $79 a month or $799 a year for 100 tests a month. Pulse has a free tier with no limits listed. Several other products on the page (Folderly AI, Lens, Mirror, DMARC) have no published price.

Best for: senders with a live problem, such as a primary domain landing in spam, who want help diagnosing it and can pay for it.

Watch-outs: price. At $96 per mailbox, 15 inboxes are $1,440 a month, roughly five times MailReach. Some third-party reviews say G2 and Capterra reviewers describe warmup volume spiking overnight without warning; we couldn't confirm that on G2 ourselves, but ask how volume is ramped.

G2: 4.8 out of 5 from about 102 reviews on Folderly on G2.

7. Mailwarm: warmup with an expert call on every plan

Mailwarm runs warmup through what its homepage calls "50,000+ aged real inboxes" that open your emails, pull them out of spam, mark them important and reply. It tracks inbox versus spam placement per mailbox, monitors spam scores and includes calls with a deliverability expert on every plan. It works with Gmail, Microsoft 365, Yahoo, Zoho and SMTP services like SendGrid, Mailgun and AWS, and alongside Instantly, lemlist and Smartlead (it tells you to switch off their built-in warmup).

Pricing, from Mailwarm pricing: Starter is $79 a month ($69 billed yearly) for 1 mailbox, up to 50 warmup emails a day and 1 expert call a month. Growth is $189 ($159 yearly) for 3 mailboxes, 200 emails a day and 4 calls. Scale is $549 ($479 yearly) for 10 mailboxes, 500 emails a day and calls on demand. Tailored is custom with unlimited mailboxes. Extra interactions are $0.02 each. There's no free trial; the page offers 20% off the first month instead.

Best for: a founder or small team with one to three important inboxes who wants a person to call when something breaks.

Watch-outs: it's the most expensive warmup per inbox here. Scale works out to $54.90 per mailbox a month, and a 15-inbox cold email setup needs a custom plan. The network size is Mailwarm's own claim, and the page doesn't say how those inboxes are sourced.

G2: reviews are few and the listings disagree. One Mailwarm listing shows 5.0 from about 15 reviews, while a separate "Mail Warm" listing shows 3.7 from 14, and we couldn't confirm whether both are the same company. See Mailwarm on G2.

8. EmailWarmup.com: warmup plus mailboxes, with a guarantee to read closely

EmailWarmup.com sells personalized warmup matched to your industry across business and consumer providers, free spam tests across what it calls 50+ ESPs with blocklist checks, and Google or Microsoft 365 mailboxes set up with SPF, DKIM and DMARC that it monitors and replaces when they degrade. Its homepage also describes a LinkedIn fallback that messages prospects when an email bounces. The logo and footer links point to Maxify, which appears to run it.

Pricing, from EmailWarmup.com pricing: Pro is $29 per mailbox a month, with annual billing listed as "3 Months Off." It includes personalized warmup, a limited deliverability test, multi-provider warmup and language selection, with Google and Microsoft mailboxes listed alongside. Enterprise is custom and adds higher volume, unlimited tests, Google Postmaster, API access and seed list warmup. There's a "Try for Free" button but no stated trial length.

Best for: teams starting from zero who want inboxes and warmup from one vendor and are happy to test the service before committing.

Watch-outs: the pricing page promises "98% Inbox Guaranteed or Money Back" but doesn't say which plans it covers or how placement is measured, and the homepage only says "Subject to our Terms of Service." Ask for those terms in writing. The page doesn't say how warmup works (real inboxes or a network) or what daily volume you get.

G2: EmailWarmup.com's G2 seller page shows 0 reviews, so there's no independent rating to check yet.

What warmup really costs

Most cold email programs send from 10 to 20 inboxes across several secondary domains, at 30 to 50 emails per inbox per day. Here is what warming 15 inboxes costs per month on each tool's published price:

• Instantly Growth: $47, since unlimited warmup comes with the sender.
• MailReach: 15 times $19.50 is $292.50, with 20 spam test credits.
• lemwarm Essential: 15 times $29 is $435, or $360 on yearly billing.
• EmailWarmup.com Pro: 15 times $29 is $435.
• Folderly: 15 times $96 is $1,440 on yearly billing.
• Mailwarm: custom, since Scale stops at 10 mailboxes for $549.

Add $59 a month for GlockApps Essential if you want 360 placement tests on top. The gap between $47 and $1,440 is why we tell most teams to start with the warmup in their sender and spend on testing, not on a second warmup network.

Warmup can't fix a bad list. Inbox placement also depends on bounce rate, which comes from list quality, and on what the email says. In our own sending, companies on Google Workspace replied at 1.35% against 0.29% for Microsoft 365, so a placement test that only checks Gmail can hide an Outlook problem. Our cold email statistics break down reply rates by provider, title and company size.

How to choose a deliverability tool

• Check what your sender already includes. Instantly lists unlimited warmup from $47 and lemlist includes lemwarm on every plan. Paying twice for warmup rarely helps, and Mailwarm itself tells you to switch one off.
• Separate warming from testing. Warmup builds history; a seed list test tells you where mail lands today. If you only buy one standalone tool, buy testing (GlockApps, MailReach credits or Warmy's tester).
• Price per inbox, not per plan. MailReach, lemwarm, EmailWarmup.com and Folderly all charge per mailbox, so multiply by your real inbox count before you compare.
• Test both Google and Microsoft. Make sure the seed list covers Microsoft 365 and Outlook, not just Gmail.
• Give it time. MailReach recommends at least 14 days of warmup before campaigns and Mailwarm says 2 to 4 weeks for a new domain. A tool that promises results in days is worth questioning.
• Get guarantees in writing. EmailWarmup.com's 98% inbox promise and Warmy's "from $49" both need written terms before you rely on them.
• Pick your sender carefully too. Our ranking of the best cold email software covers which senders include warmup and on which plans.

When to hire an agency instead

Warmup tools keep inboxes healthy. They don't buy and configure domains, rotate tired mailboxes out, keep bounce rates low with clean data, or write emails people want to answer. If no one on your team will watch placement every week, the inboxes slowly slide into spam and nobody notices until replies stop.

An agency makes sense when you have a sales team that can take meetings and a contract value high enough that a few extra deals pay for the service. IntentSignal is a B2B cold email agency. We set up and warm the sending infrastructure on domains and mailboxes you own in writing, build AI research agents for each client, and programs start at $2,999 a month, month to month. Route got 117 opportunities in one month with us; Gainsight got 90 sales-accepted leads in two months.

We're email-led. If your buyers mostly answer the phone, a phone-first agency fits better, and our cold email agency rankings and cold email agency pricing guide show the options and what they cost. Weighing specific agencies? See our Belkins alternatives and CIENCE alternatives breakdowns.

Book a campaign plan call and we'll show you the accounts and angles we'd start with, or tell you to keep running it yourself.

Frequently asked questions

What is the best email deliverability tool in 2026?

For a standalone tool, Warmy: warmup, a 500K+ US seed list, placement tests, DMARC monitoring and blacklist alerts from $49 a month, with a 7-day free trial and 4.8 stars from about 525 G2 reviews. If you send with Instantly or lemlist, start with the warmup they include and add a placement tester like GlockApps.

Do I need a separate warmup tool if my cold email software has warmup?

Usually not. Instantly lists unlimited warmup from its $47 Growth plan and every lemlist plan includes lemwarm. Add a separate tool when placement tests show a problem, or when you want independent spam tests. Don't run two warmup tools on the same inbox; Mailwarm's own FAQ warns that it doubles your volume.

What is the cheapest email warmup tool?

If your sender includes it, built-in warmup is cheapest: Instantly Growth is $47 a month for unlimited inboxes. Among standalone tools, MailReach showed $19.50 per mailbox a month with 20 spam test credits, and lemwarm Essential is $29 per mailbox ($24 yearly).

How long should I warm up a new email inbox?

Two to four weeks before sending campaigns. MailReach recommends at least 14 days with no campaigns, and Mailwarm says 2 to 4 weeks for a new domain, starting around 10 to 20 emails a day and raising volume gradually.

What is the difference between warmup and an inbox placement test?

Warmup sends and receives emails with a network of inboxes to build a sending history. A placement test sends your real email to a seed list and reports whether it landed in the inbox, spam or promotions at each provider. GlockApps only tests; Warmy and MailReach do both.

Is Folderly worth the price?

Only if you have a problem you can't fix yourself. Folderly is $96 per mailbox a month on yearly billing, so 15 inboxes cost $1,440 a month. It holds 4.8 stars from about 102 G2 reviews, and its Inbox Insights testing product has a free plan with 2 tests a month you can try first.

Does EmailWarmup.com really guarantee 98% inbox placement?

Its pricing page says "98% Inbox Guaranteed or Money Back," but neither the pricing page nor the homepage explains which plans qualify or how placement is measured; it points to its terms of service. Ask for the conditions in writing. It also has no reviews on G2 yet.

Sources

• Warmy pricing
• Warmy homepage (features, free tools)
• MailReach pricing
• Instantly pricing
• lemwarm pricing
• GlockApps pricing
• Folderly pricing
• Mailwarm pricing
• Mailwarm homepage (network, integrations, FAQ)
• EmailWarmup.com pricing
• EmailWarmup.com homepage (features, guarantee badge)
• Warmy on G2 (4.8, about 525 reviews)
• MailReach on G2 (4.7, 44 reviews)
• Instantly on G2 (4.8, 4,163 reviews)
• lemlist on G2 (4.6, 2,570 reviews)
• GlockApps on G2 (4.1 to 4.2, 26 to 27 reviews)
• Folderly on G2 (4.8, about 102 reviews)
• Mailwarm on G2
• EmailWarmup.com on G2 (0 reviews)
• IntentSignal cold email statistics