Best Email Warmup Tools in 2025: Lemwarm vs Warmy vs Mailreach vs MailPilot

The email warmup tool market has consolidated around a handful of players: Lemwarm, Warmy, Mailreach, Folderly, Mailivery, and Instantly (which bundles warmup with its sequencer). We ran each through a standardized test protocol across 30 days to compare pool size, inbox placement outcomes, pricing transparency, and support quality. Here is our full breakdown.

The Tools We Tested

Lemwarm (by Lemlist)

Lemwarm is the oldest dedicated warmup tool in the market. Its pool of approximately 10,000 users is exclusively Lemlist customers - which creates a closed-loop network. Inbox placement results in our test averaged 88% on Gmail and 91% on Outlook after 30 days. Pricing starts at $29/month per mailbox with no bulk discount until 10+ seats. The main limitation is that you must use Lemlist's ecosystem; standalone Gmail or Outlook accounts require workarounds.

Warmy.io

Warmy positions itself on AI-generated warmup email content, claiming its copy avoids spam filters better than generic warmup emails. In our test, placement results were comparable to Lemwarm (86% Gmail, 90% Outlook) but warmup took 5–7 extra days to stabilize, suggesting the AI content didn't provide a meaningful advantage over well-crafted generic templates. Pricing at $49/month per mailbox is on the high end for results delivered.

Mailreach

Mailreach focuses specifically on spam score reduction rather than raw volume warming. Its "spam test" feature — which shows you which inbox providers would classify your email as spam before you send — is genuinely useful. Inbox placement results averaged 91% Gmail, 94% Outlook in our test. Pricing at $25/month per mailbox is competitive. The weakness is a smaller pool that can feel repetitive on the same receiving end after 3+ weeks.

Folderly

Folderly targets enterprise accounts and backs its product with an inbox placement guarantee. Setup is more complex than competitors, requiring email forwarding configuration. Results in our test were among the strongest: 93% Gmail, 96% Outlook after 30 days. Pricing is higher ($120+/month per domain) and requires a sales call, making it inaccessible for small teams or individual senders.

Mailivery

Mailivery has a solid warmup pool and a clean dashboard. Inbox placement results in our test averaged 89% Gmail, 92% Outlook. Their standout feature is detailed per-provider placement breakdowns, which help you diagnose issues with specific inbox providers. Pricing at $39/month per mailbox is mid-range. The platform is less polished than competitors for multi-mailbox management.

Instantly Warmup

Instantly bundles warmup with its cold email sequencer. If you're already using Instantly to send campaigns, the included warmup is a strong value. Standalone, it's less compelling: the pool quality is inconsistent, and inbox placement results averaged 84% Gmail, 88% Outlook — the lowest in our test group. Best for Instantly users; not the right choice if you want warmup-only.

How MailPilot Compares

MailPilot's warmup pool spans 8,400+ real mailboxes across Gmail, Outlook, Yahoo, and independent providers. In the same 30-day test protocol, MailPilot achieved 95% Gmail and 97% Outlook inbox placement — the highest of any tool tested. Pricing starts at $19/month per mailbox with transparent bulk discounts, no sales calls required, and full multi-provider support including SMTP and Google Workspace accounts.

Recommendation

For most cold email senders, MailPilot or Mailreach represent the best value. Folderly is worth the premium for enterprise accounts where deliverability guarantees matter. Avoid Instantly Warmup as a standalone tool. Lemwarm is acceptable if you're already in the Lemlist ecosystem but isn't worth the switch cost otherwise.

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