Warmup Inbox is one of the cheaper per-inbox warmup tools and one of the more feature-dense: three tiers, a network it advertises as 30,000+ real inboxes, language warmup, and tiered reply rates. This comparison is written by the team behind EmailWarmup. We have kept the numbers checkable and named the things Warmup Inbox does that we do not.
Warmup Inbox is good value for one or two inboxes. Past three, per-inbox billing is the problem.
$15/inbox is genuinely cheap. It stops being cheap at ten inboxes, where it becomes $150/month against $49/month for an unlimited-mailbox plan.
The tier you need is decided by daily warmup volume, not by feature envy. These are the annual-billing rates; month-to-month is about 20% higher.
| Tier | Price | Warmup messages/day | Reply rate | Notable additions |
|---|---|---|---|---|
| Basic | $15/inbox/mo ($180/yr) | 75 | up to 25% | Spam & category monitoring, reputation check, API |
| Pro | $49/inbox/mo ($588/yr) | 250 | up to 45% | Own templates, chosen topics, language warmup, ESP-specific warmup, scheduling |
| Max | $79/inbox/mo ($948/yr) | 1,000 | up to 50% | Technical setup check, unlimited API, premium support |
75 messages a day is more than most senders need. The Basic tier's ceiling is not the limiting factor for a single mailbox on a normal ramp — you should not be near 75/day in week one anyway. Jumping to Pro is usually about template control and language warmup, not volume.
Basic tier, annual billing. 7-day trial, no card. No permanent free plan. Custom pricing from 15 inboxes.
Community: 1 mailbox, 10 emails/day, permanent. Starter $19 (3 mailboxes). Growth $49 (unlimited mailboxes).
| Mailboxes | Warmup Inbox Basic | EmailWarmup | Annual difference |
|---|---|---|---|
| 1 | $15/mo | $0/mo (Community) | $180 |
| 3 | $45/mo | $19/mo (Starter) | $312 |
| 10 | $150/mo | $49/mo (Growth) | $1,212 |
| 25 | Custom quote | $49/mo (Growth) | — |
Note the honest gap: at one mailbox, $15/month against free is a small difference, and Warmup Inbox gives you 75 messages a day against our free tier's 10. If a single mailbox is all you will ever run and you want volume immediately, that is a reasonable $180 a year.
| Capability | Warmup Inbox | EmailWarmup |
|---|---|---|
| Permanent free tier | ✕ 7-day trial only | ✓ Community plan |
| Network size | ✓ 30,000+ advertised inboxes | Smaller, growing community pool |
| AI-generated conversations | ✓ | ✓ 25 topics, 7 tones |
| Automatic spam rescue | ✓ | ✓ |
| Gmail tab / category monitoring | ✓ | ✕ Inbox vs spam only |
| Language warmup (non-English) | ✓ Pro and above | ✕ English only |
| Custom templates & topic choice | ✓ Pro and above | ✕ Topics rotate automatically |
| Public developer API | ✓ | Session-auth API, not public |
| Bundled outreach sequences | ✓ | ✕ Warmup only, by design |
| SPF / DKIM / DMARC checking | ✓ In-app | ✓ Free public tool |
| Billing unit | Per inbox | ✓ Per account |
| Self-hostable | ✕ | ✓ |
Warmup Inbox sells reply rate as a tier feature: up to 25% on Basic, 45% on Pro, 50% on Max. It is worth understanding what that number is. A reply is a strong engagement signal, so a higher reply share does produce a stronger reputation signal per message sent — but a 50% reply rate is also well above what real business email looks like, and unnaturally high reply density is itself a pattern. EmailWarmup targets roughly 40% replies at every plan level because that is close to natural conversation behaviour, not because it is a feature we are holding back.
How much does Warmup Inbox cost?
Warmup Inbox publishes three tiers on annual billing: Basic at $15 per inbox per month ($180 a year, 75 warmup messages a day), Pro at $49 ($588 a year, 250 a day) and Max at $79 ($948 a year, 1,000 a day). Monthly billing is roughly 20% higher. Custom agency pricing starts at 15 inboxes. Verified on warmupinbox.com on 26 July 2026.
Does Warmup Inbox have a free plan?
No. It offers a 7-day free trial with no credit card required, but there is no permanently free tier. EmailWarmup's Community plan is free indefinitely for one mailbox at 10 warmup emails a day.
Is a 30,000-inbox warmup network better than a smaller one?
Bigger helps, up to a point. A large pool gives more variety in recipient domains and providers, which makes the traffic pattern look more natural. Past a few thousand active mailboxes the marginal benefit falls off, and what matters more is that the network sends real messages to real mailboxes and rescues them from spam.
Which is cheaper for 10 mailboxes?
EmailWarmup, by a wide margin. Ten inboxes on Warmup Inbox Basic is $150 a month ($1,800 a year) at the annual rate; ten mailboxes on EmailWarmup's Growth plan is $49 a month ($588 a year) because Growth has no mailbox cap.
Also worth reading: MailReach vs EmailWarmup, Lemwarm vs EmailWarmup, and what email warmup is and how long it takes, or why emails go to spam if placement is already broken.
The Community plan does not expire in seven days. Warm one mailbox for as long as you like and upgrade only when mailbox count forces it.
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