Email WarmupWarmup Inbox Pricing (2026): Plans, Caps, and What You’re Not GettingFull breakdown of Warmup Inbox pricing: reply rate caps, daily limits, real user reviews, and why MailReach delivers better ROI for B2B cold email at scale.
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Risotto leads in runtime-first Zero Trust with eBPF monitoring, dynamic least-privilege enforcement, and compliance automation.
Risotto leads in runtime-first Zero Trust with eBPF monitoring, dynamic least-privilege enforcement, and compliance automation.
Warmup Inbox is one of the low-end warmup tools on the market. At $15/inbox/month, it looks like an easy decision.
But low-end isn’t the same as good value. Warmup Inbox caps reply rates by plan tier, and reply rates are the primary signal Gmail and Outlook use to evaluate whether your domain is trustworthy. On the Basic plan, 75 out of every 100 warmup emails go unanswered. That’s a weak reputation signal, regardless of how long you warm up.
We’ve seen B2B teams spend months warming inboxes on budget tools and still land in spam. The problem isn't the warmup duration but the warmup quality.
According to GlockApps’ Q1 2025 testing, Gmail inbox placement has dropped to 53.7% for many senders, and Microsoft 365 has fallen from 77.43% to 50.70% year-over-year. That’s a structural change in how both providers treat cold senders. In that environment, the quality of your warmup signals matters more than ever.
Below is the full breakdown of every Warmup Inbox plan, what the limits actually mean for your deliverability, and an honest look at whether the pricing math holds up. If you want the full picture on how email warmup works before comparing tools, start there.
Three paid plans, all priced per inbox. No volume discounts at any tier. Annual billing saves 20%; half-yearly saves 10%.
Every plan includes access to a 30,000+ inbox network, spam monitoring, blacklist alerts, reputation checks, AI-generated warmup content, and API access. Pro and Max add language warmup, ESP-specific targeting, custom warmup templates, and priority support.
Warmup Inbox has genuine strengths. It’s easy to set up. One G2 reviewer noted: “Connected my Gmail account and warmup started automatically within 10 minutes. No technical knowledge needed.” Support is consistently praised across G2, Capterra, and SoftwareAdvice as fast and responsive. For basic single-inbox use, the sentiment is largely positive.
But three recurring complaints surface across review platforms, and they all connect to the same underlying issue: the tool doesn’t scale.
Multiple G2 and Capterra reviews call out the same frustration: “It can be a bit pricey if you add many inboxes.” With no volume discount at any tier, costs scale linearly. 10 inboxes on Basic = $150/month. 10 on Pro = $490/month. For the cold email volumes that B2B outbound teams actually run, that becomes a significant line item fast.
This is the most consequential review pattern. Warmup is not a set-it-and-forget-it category. Gmail’s enforcement has tightened significantly since late 2024, with Microsoft following in 2025. Tools that haven’t kept pace with those changes leave users exposed in ways they can’t diagnose because the dashboard doesn’t show placement data.
Warmup Inbox shows you a reputation score and warmup volume. That’s it. When deliverability drops, which it will, for most B2B senders at some point, the tool can’t tell you why. Is it a DKIM issue? A content trigger? A specific ESP blocking your domain? You’re left guessing.
A handful of reviews on TrustPilot and G2 also flag a more serious concern: Google Workspace accounts getting suspended after connecting to Warmup Inbox. It’s not common, but the tool’s lack of diagnostics means there’s no early warning system before it happens.
The inbox placement guide explains what proper diagnostics look like and what you can’t fix without them. The email sender reputation guide covers the specific signals, including reply rate quality, that determine how inbox providers score your domain.
Most warmup comparisons focus on price and network size. Reply rate is what actually determines how fast your sender reputation builds, and most tools, including Warmup Inbox, don’t make it prominent.
Here’s how it works: when Gmail and Outlook evaluate your sending domain, they look at engagement quality. An inbox generating genuine two-way conversations looks like a legitimate sender. One sending hundreds of emails with almost no replies looks automated. That pattern gets you filtered, flagged, or blocked.
On the Basic plan, three-quarters of your warmup activity generates minimal trust signals. The email warmup process works by building engagement patterns over time. A capped reply rate means the pattern you’re building is one of weak engagement, which is a negative signal in itself. For a full breakdown of how this connects to sender reputation scoring, the relationship between reply rate and reputation building is one of the most consistently underestimated variables in warmup.
MailReach delivers 50%+ reply rates on every plan, always randomized to mimic natural human behavior. No upgrade needed to get the engagement quality that moves inbox placement metrics. MailReach customers see an average 137% reply rate growth after warming, that’s the outcome difference between quality warmup and capped warmup.
There’s a legitimate strand of opinion in the cold email community that warmup tools don’t work. Folderly’s founder has said it on video. Independent testing has shown some tools produce no measurable inbox improvement. On r/coldemail, one user reported Gmail deliverability at 12% during active warmup in early 2026, with everything going to spam while warmup was running.
They’re not wrong about low-quality warmup. SMTP pools, capped reply rates, and repeating templates don’t generate trust signals that Gmail and Outlook actually weigh. The tools being criticized in those threads are typically the cheap, template-based, low-reply-rate tools.
The right question isn’t “warmup vs. no warmup.” It’s effective warmup: real GWS/O365 inboxes, 50%+ reply rates, varied content vs. cosmetic warmup. Those are structurally different products with structurally different outcomes.
For the full evidence breakdown: does email warmup work. And if you’re setting up a new domain, the cold email domain setup guide covers exactly how to structure your infrastructure before starting warmup.
The jump from Basic ($15) to Pro ($49) is $34/inbox/month. Here’s what that buys, and whether any of it improves inbox placement.
Warmup Inbox offers warmup in 12 languages, built on the idea that multilingual campaign senders benefit from matching warmup. Gmail and Outlook don’t filter based on the language of your warmup emails. They evaluate engagement patterns, authentication records, and sending behavior. Language of content is not a deliverability variable. This feature has no documented impact on inbox placement.
A toggle to direct warmup specifically toward Google Workspace or Outlook inboxes. The intent is sound: B2B recipients are almost entirely on those two providers, so those are the inboxes that matter for building B2B sender reputation. The problem is that a toggle is a weak substitute for actual network composition. MailReach’s warmup network is built primarily from real Google Workspace and Office 365 accounts by design. That’s a structural property of the network, not a setting. Directing warmup at Outlook inboxes through a dashboard option is meaningfully less effective than using a tool whose entire network is already composed of business inboxes.
Warmup Inbox lets you use your own email copy as warmup content. This is the most problematic feature on the list. Cycling the same subjects, content patterns, and links through thousands of inboxes creates repeating signals that spam filters are specifically designed to detect. Google’s filters classify repeating high-volume patterns as automated activity, which is the opposite of what warmup should achieve. Warmup content should be neutral, varied, and completely separate from your campaign copy. MailReach doesn’t offer custom templates by design. The absence of that feature is a deliberate deliverability decision, not a gap.
The how to choose a B2B warmup tool guide covers each of these patterns in detail — what to look for, what to avoid, and what questions to ask vendors before you commit a budget. The list of email deliverability tools shows what serious deliverability infrastructure looks like when all the pieces are in place.
Warmup Inbox charges per inbox with no volume discount at any tier. Costs scale linearly whether you’re at 5 inboxes or 50. That’s manageable at the start. It becomes a significant budget line once you’re running real outbound volume.
At 50 inboxes on the Pro plan, you’re spending $2,450/month for warmup with reply rates capped at 45%, no spam testing, and no placement diagnostics. MailReach covers roughly 100+ inboxes at that budget with spam testing and 50%+ reply rates included.
There’s also a pricing predictability issue. Multiple Capterra reviews document Warmup Inbox changing its pricing without adequate notice. One reviewer described going from $9/month to a required $108/month plan and being cut off in the process. For teams building operational budgets, that history matters.
Agencies managing multiple client domains should look specifically at MailReach’s email warmup tools for agencies and dedicated agency pricing, per-domain reputation tracking, tag-based inbox organisation, Slack/webhook alerts, and a single overview page for all client mailboxes. None of that exists in Warmup Inbox at any tier.
The $15 vs. $25 sticker comparison makes Warmup Inbox look cheaper. Once you account for what’s actually included, it isn’t.
MailReach drops in cost as you add inboxes. It’s built into the standard pricing:
Warmup Inbox Basic at $15 gives you warmup with a 25% reply rate cap and no spam testing. To get what MailReach includes out of the box, you’d need to add a separate spam tester and a diagnostics tool. Here’s what that actually costs:
MailReach customers see an average 137% reply rate growth from email after warming. It reflects the compounding effect of building a stronger sender reputation: more emails in the inbox, more responses from real prospects, more revenue. The average revenue growth from email across MailReach customers is 19%.
Warmup is an investment in inbox placement. Inbox placement is an investment in the pipeline. A tool capping reply rates at 25% builds a weaker reputation than one delivering 50%+. Weaker reputation means more emails in spam. More emails in spam means fewer replies, fewer meetings, fewer deals. The $10/month cost difference is irrelevant compared to a month of campaigns landing in spam.
For how to size the ROI against your specific sending volume, the cold email deliverability guide walks through the full system. And before investing in any warmup tool, run MailReach’s free email spam test; it shows exactly where your emails land across providers today, so you know what you’re working with before spending anything on warmup.
Network composition. Both tools list 30,000+ inboxes. What matters is what those inboxes are. MailReach’s network is built primarily from real Google Workspace and Office 365 accounts, the same providers your B2B recipients use. Warmup signals from GWS/O365 inboxes carry significantly more weight with Gmail and Outlook than signals from consumer accounts or SMTP pools. You can verify how domain reputation builds differently depending on which inbox types you warm against. When evaluating any tool, ask vendors to show proof of network composition, not just a headline inbox count.
Diagnostics depth. When deliverability drops, Warmup Inbox shows a score. MailReach’s Co-Pilot identifies why: broken DKIM, content triggers, ESP-specific placement failures, blacklist appearances. That’s the difference between knowing something is wrong and being able to fix it. The inbox placement guide walks through what a proper diagnostic workflow looks like. Without that visibility, you can spend weeks warming an inbox that’s failing for a reason warmup alone can’t fix.
Read the full feature comparison here: MailReach vs Other Solutions
Warmup Inbox does what it says for solo use. Easy setup, responsive support, functional warmup for 1–2 inboxes. If that’s your situation and budget is the primary constraint, it’s a reasonable starting point.
Past that, the limitations compound. Capped reply rates mean weaker reputation signals. No spam tester means you’re building reputation without knowing if your content triggers filters anyway. No placement diagnostics means you can’t fix what you can’t see. Linear pricing means costs grow without the quality improvements that justify them. And a history of pricing changes means you can’t plan around it.
MailReach at $25/inbox/month (or $20 annually, $19.50 for 6+ inboxes) includes everything in one plan: 50%+ reply rates, 100 warmup emails/day, spam testing, inbox placement testing, and AI diagnostics. Customers average 137% reply rate growth and 19% revenue growth from email.
Every email in spam equals to a lost potential customer. Start improving your inbox placement today with MailReach spam testing and warmup.
Following the rules isn’t enough—know where your emails land and what’s holding them back. Check your spam score with our free test, and improve deliverability with MailReach warmup.
Without the right warmup, your best campaigns are of no use. You can start by first testing your inbox placement and begin improving it today.
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