14 Best Email Warmup Tools in 2026 (Real Pricing Compared)

The best email warmup tool for most senders is Warmerly ($19/month flat for 5 mailboxes, $49 for 25) if you already have a campaign tool, or Smartlead ($39/month for 10 mailboxes) if you want warmup and campaign sending bundled in one place. Below are all 14 worth considering in 2026, with real pricing and what each one is actually best for.

Email warmup tools all do roughly the same core thing: send and receive mail between real mailboxes, generate opens and replies, and rescue messages that land in spam — so mailbox providers see a real, engaged sender instead of a brand-new or dormant one. The differences that matter are the pricing model (per-mailbox vs flat rate adds up fast past 5 inboxes), how aggressively they rescue spam-folder mail, and whether warmup is the whole product or a feature bolted onto a campaign sender.

What to compare before you pick one

• ✦Pricing model — per-mailbox pricing gets expensive quickly once you manage more than a handful of inboxes; flat-rate tools don't
• ✦Spam-recovery speed — how often the tool scans and rescues messages that land in spam (10 minutes vs 30+ makes a real difference)
• ✦Standalone vs bundled — do you want warmup only, or warmup plus a campaign sender in the same tool
• ✦Authentication monitoring — daily SPF/DKIM/DMARC checks catch problems before they burn a domain
• ✦Free trial — most reputable tools offer one so you can see spam-recovery data before paying

1. Warmerly — best flat-rate warmup per mailbox

Warmerly is warmup-only: no bundled campaign sender, which means it plugs into whatever you already use for outreach. $19/month covers 5 mailboxes and $49 covers 25, so it's the cheapest option by a wide margin against anything priced per inbox. Spam-folder rescue runs every 10 minutes, and it monitors SPF, DKIM, DMARC, and MTA-STS daily with remediation steps when something breaks.

2. Instantly — best if you want warmup bundled with a campaign engine

Instantly is the most recognized name in the category — a full cold-email platform with warmup included. Starting tier is $37/month with a limited mailbox allowance, so cost scales up fast if you're running more than a few sending accounts. Good choice if you want one tool for both sequences and warmup and don't mind paying more for the convenience.

3. Smartlead — best all-in-one with strong API access

Smartlead bundles warmup with a campaign sender and has the strongest API in the category, which matters if you're building custom tooling around your outreach stack. $39/month gets you 10 mailboxes, cheaper than Instantly's equivalent tier. The warmup peer network mixes providers well.

4. Mailreach — best for warmup with a built-in deliverability score

Mailreach is warmup-focused like Warmerly, with a deliverability scoring dashboard that shows inbox placement trends over time. Priced around $25/month per mailbox, so it's per-inbox rather than flat-rate — worth running the math if you manage several accounts.

5. Lemwarm — best if you're already on lemlist

Lemwarm is lemlist's warmup product, tightly integrated with lemlist campaigns. $29/month per mailbox. Only worth it if you're already a lemlist customer running sequences there — the price stops making sense as a standalone warmup tool.

6. Warmbox — best budget standalone warmup

Warmbox is a lighter-weight standalone warmup tool, priced roughly $19-69 per inbox per month depending on tier (verify current pricing at warmbox.io — it changes). Reasonable option if you want something simpler than the bigger platforms and don't need deep deliverability monitoring.

7. Mystrika — best for a free single-mailbox tier

Mystrika is the only tool on this list with a genuine free tier for a single mailbox, with paid plans from roughly $19/month once you add more (verify at mystrika.com). Good for testing warmup on one domain before committing spend.

8. Mailwarm — best simple, no-frills option

Mailwarm keeps the feature set minimal — warmup without a dashboard full of extras. Priced around $69/month per mailbox, which makes it one of the more expensive per-inbox options on this list, but the setup is genuinely fast if you just want warmup running with no configuration.

9. Folderly — best for teams that want deliverability consulting alongside warmup

Folderly pairs warmup with more hands-on deliverability guidance, starting around $120+/month (verify at folderly.com). The higher price reflects the added consulting layer — worth it if you want expert eyes on a deliverability problem, overkill if you just need warmup running.

10. Warmy.io — best for high-volume senders who want a managed relationship

Warmy.io is the most heavily resourced deliverability platform on this list: it advertises a 1M+ mailbox warmup network, a 500K+ US seed list for placement testing, an AI co-pilot called Adeline, and a dedicated expert on 24/7 support. It no longer publishes prices — the pricing page lists B2B sender, B2C sender and Custom tiers with identical feature lists and no figures, describing the model as volume-based, so you get a number from the 7-day free trial or a demo. Worth the conversation if you send at high B2C volume; skip it if you want to know the cost before you commit. Not to be confused with Warmly.ai, which is a website-visitor-identification tool and does no warmup at all.

11. Warmup Inbox — best for a single mailbox on the lowest price

Warmup Inbox is warmup-only and priced strictly per inbox: $15/inbox/month on Basic, $49 on Pro, $79 on Max, with 20% off annually and custom pricing past 15 inboxes. For one mailbox that is the cheapest entry on this list. The model is worth doing the arithmetic on before you commit, though — five inboxes on Basic is $75/month and twenty-five is $375, because every tier multiplies by inbox count.

12. Mailivery — best for many mailboxes warmed lightly

Mailivery connects unlimited mailboxes on every plan and prices by daily warmup volume instead: $29/month Starter, $79 Professional, $199 Business, with roughly 25% off annually. That is the right shape if you need dozens of inboxes warmed a little each. The trade is that all those mailboxes share one daily volume pool, so warmup per mailbox thins as you add more and the fix is a tier upgrade.

13. Saleshandy — best if you want unlimited mailboxes on a sequencing platform

Saleshandy is a full cold-email platform - sequences, deliverability tooling, a lead database - and it includes warmup on every plan with unlimited email accounts, from $34/month. Daily warmup volume limits apply per tier, but the connection count does not, which makes it good value once you are running a lot of mailboxes. Warmup is a bundled feature here rather than the centre of the product, so weigh it on the sequencing side.

14. Snov.io — best if you want prospecting, CRM and outreach in one

Snov.io is a credit-based sales platform covering email finding, verification, sequences and a CRM, with warmup sold as slots: 3 on the $39 Starter, unlimited from $99 Pro S upward. If you want the whole prospecting motion in one subscription it is a reasonable buy. If warmup is specifically what you are shopping for, count the slots before the headline price - $39 warms three mailboxes.

How to choose

• ✦Warmup only, lowest cost per mailbox → Warmerly
• ✦Warmup + campaigns in one platform, don't mind the price → Instantly
• ✦Warmup + campaigns, strong API → Smartlead
• ✦Already on lemlist → Lemwarm
• ✦Want a deliverability score dashboard → Mailreach
• ✦Want to test on one mailbox for free → Mystrika
• ✦Want deliverability consulting, not just software → Folderly
• ✦High-volume B2C sending with a dedicated expert → Warmy.io
• ✦Exactly one mailbox, lowest price → Warmup Inbox
• ✦Dozens of mailboxes warmed lightly → Mailivery
• ✦Unlimited mailboxes on a sequencing platform → Saleshandy
• ✦Prospecting, CRM and outreach in one → Snov.io

If you're only solving for warmup — not campaigns — the flat-rate tools (Warmerly, and to a lesser extent Warmbox) will almost always cost less than a per-mailbox tool once you're past a handful of inboxes. Pair a dedicated warmup tool with whatever campaign sender you already use, rather than paying platform prices for a feature you could get standalone.