Warmup Inbox Alternative: Warmuply vs Warmup Inbox

Looking for a Warmup Inbox alternative? You're probably about to send a mail merge from your work address, or you already did and the replies didn't come. This page puts Warmup Inbox and Warmuply side by side so you can see which one fits the way you send.

Warmup Inbox is a well-known tool built mainly for cold email and sales teams. Warmuply is built for people who send a mail merge from their own Google Workspace address using YAMM, Gmail's built-in mail merge, GMass or Google Sheets. Neither is "better" across the board. The right pick depends on how many inboxes you run, which email provider you use, and how you send.

Every Warmup Inbox detail below comes from its own website, checked in October 2026. Prices and features change, so confirm them on its pricing page before you buy.

Warmuply vs Warmup Inbox at a glance

Warmup Inbox is a broad warmup platform for teams with many inboxes on many providers. Warmuply is a focused tool for one Google Workspace address sending a mail merge. Here's how they compare.

What is Warmup Inbox?

Warmup Inbox is an email warmup service. You connect your inbox, and it exchanges everyday-looking emails with a network it says has more than 30,000 real inboxes. Those emails get opened and replied to, which builds your sender reputation: the trust Gmail, Outlook and other providers have in your address and domain.

The company behind it, CyberPanda s. r. o., describes the product as "built by cold-email senders, for cold-email senders." That shows in the features. Beyond warmup, Warmup Inbox offers cold email sequences, warmup for dedicated IP addresses, warmup in other languages, a developer API, and a long list of free tools, including a placement test you can run without signing up.

You connect a Gmail or Google Workspace inbox with OAuth, which means you sign in with Google and approve access, without sharing your password. It also supports Microsoft 365, Yahoo, Zoho and any email provider that connects over SMTP, the standard way email servers send mail.

Warmup Inbox has pages for sales teams, marketers, agencies and recruiters. Its pricing is per inbox, with discounts as you add more and custom quotes past 50 inboxes. That setup works well for teams running dozens of sending addresses.

What is Warmuply?

Warmuply warms up a Google Workspace inbox in the background. It sends and receives everyday-looking emails with a network of inboxes, a little more each day, so Gmail and Outlook come to see your address as a normal, active sender.

Each day, Warmuply shows you a safe-send number: how many emails your inbox can safely send today. You enter that number in YAMM, Gmail's mail merge, GMass or whatever you already use. Nothing changes in how you send.

Warmuply also:

• checks your domain's SPF, DKIM and DMARC settings and explains problems in plain English, with the exact text to paste
• runs placement tests showing whether your email lands in the inbox, the Promotions tab or spam at Gmail, Outlook and Yahoo
• sends a blacklist alert the same day if your domain gets listed, with steps to get off

It's made for people who email in bulk from their own address but aren't email marketers. It doesn't send campaigns, and it doesn't try to replace your mail merge tool. You can see the full feature list on the Warmuply homepage.

If warmup itself is new to you, start with our guide to what email warmup is and whether you need it.

How do Warmup Inbox and Warmuply prices compare?

Warmup Inbox charges per inbox, based on how many warmup emails a day that inbox exchanges. Warmuply charges by how many mail merge emails you plan to send a day. Because they measure different things, the cheapest option depends on your situation.

Warmup Inbox's plans, as listed on its pricing page:

The listed prices are for annual billing. Warmup Inbox says annual billing saves 20% compared with paying monthly, so month-to-month costs more.

Warmuply's plans:

Warmuply’s prices are per month, and you can cancel anytime.

What this means for one inbox

Say you're sending a mail merge from one Google Workspace address.

• Up to 100 emails a day: Warmuply costs $9 a month. Warmup Inbox's lowest plan is $15 a month on annual billing.
• Up to 500 or 1,000 emails a day: Warmup Inbox's Basic plan, at $15 per inbox, costs less than Warmuply's $29 or $49 plans.

That second point is worth knowing. Warmup Inbox's plan sets how many warmup emails your inbox exchanges, not a cap on your own sending. Warmuply's plan is matched to the size of mail merge you're planning, and every plan includes the safe-send number, plain-English domain checks, placement tests and blacklist alerts. Compare what each price covers, not only the number.

What about several inboxes?

Warmup Inbox lowers the price per inbox from your second one and quotes a custom price past 50 inboxes. Warmuply charges extra for each additional inbox; see the pricing section on the homepage. If you run many sending addresses, Warmup Inbox's pricing is built for that.

How do you know how many emails you can safely send?

Warmuply gives you one number to follow each day. Warmup Inbox gives you dashboards and general guidance, and you decide the volume yourself.

Warmup Inbox tracks inbox, spam and bounce rates and shows a sender reputation score. A bounce is an email that couldn't be delivered, usually because the address doesn't exist. For sending during warmup, its FAQ suggests keeping campaign volume low, around 20 to 50 emails a day, for the first few weeks.

Warmuply's safe-send number goes up as your inbox warms. You can send while warming, as long as you stay at or below that day's number. For a mail merge, that's the main decision you have to make: how many rows of your spreadsheet to send today.

For a rough plan before you start, try our free warmup schedule calculator.

To understand where daily limits come from, read our guide to how many emails you can send a day without landing in spam.

How long does warmup take with each tool?

Both tools say warmup takes a few weeks, and neither can promise a timeline.

Our guide to how long email warmup takes walks through the timeline day by day.

How do domain checks, placement tests and blacklist alerts compare?

Both tools check your domain settings, show where your email lands, and watch for blacklists. The difference is mostly in how much they explain and who they're written for.

Domain settings

Your domain's settings decide whether providers believe your email really comes from you:

• SPF lists which servers may send email for your domain.
• DKIM adds a digital signature that proves the email wasn't changed on the way.
• DMARC tells providers what to do with email that fails those checks.

These live in your DNS, the settings for your domain held by your domain host. Warmup Inbox includes DNS, SPF and DKIM checks, offers free SPF and DMARC generators, and adds a technical setup check on its Max plan. Warmuply checks SPF, DKIM and DMARC, explains any problem in plain English, and gives you the exact text to paste into your domain settings.

You can check your domain now with our free SPF, DKIM and DMARC checker.

Placement tests

A placement test sends a test email to sample inboxes and shows where it lands: the main inbox, a tab like Promotions, or spam. Warmup Inbox includes spam and category monitoring on every plan and has a free placement test tool. Warmuply runs placement tests at Gmail, Outlook and Yahoo and tells you the likely reason if something's wrong.

Blacklists

A blacklist is a public list of domains and servers reported for sending spam. Many providers check these lists before delivering email. Warmup Inbox says it monitors blacklists and runs an automatic rescue process to get a listed inbox removed. Warmuply alerts you the same day your domain is listed and gives you the steps to get off the list.

Which email accounts does each tool work with?

Warmup Inbox works with almost any provider. Warmuply works only with Google Workspace on your own domain, such as you@yourcompany.com.

Warmup Inbox supports Gmail, Google Workspace, Microsoft 365, Yahoo, Zoho and any provider that connects over SMTP. It also lists integrations with ESPs (email service providers, the services businesses use to send newsletters and transactional email) such as Amazon SES, SendGrid and Mailgun.

Warmuply supports Google Workspace addresses on your own domain. Microsoft 365 and other providers aren't supported yet. If your business email runs on Outlook or Microsoft 365, Warmup Inbox can help you today and Warmuply can't.

When is Warmup Inbox the better choice?

Warmup Inbox is the better fit if your sending looks more like a sales or agency team than a single mail merge. Pick it if you:

• run many inboxes or manage sending for clients, and want one dashboard with volume pricing
• send from Microsoft 365, Zoho, Yahoo or another SMTP provider
• want warmup and cold email sequences in the same tool
• need custom warmup settings, warmup in other languages, warmup for a dedicated IP address, or an API
• send 500 or more emails a day from one inbox and want the lowest price per inbox

When is Warmuply the better choice?

Warmuply is the better fit if you send a mail merge from one Google Workspace address and want a clear answer, not a dashboard to interpret. Pick it if you:

• send with YAMM, Gmail's built-in mail merge, GMass, Google Sheets and Apps Script, or by hand, and don't want to change that
• want one number each day that tells you how many emails to send
• aren't technical and want domain problems explained in plain English, with text to paste
• send around 100 emails a day or fewer and want the lowest price ($9 a month)
• want placement tests and blacklist alerts included in every plan

What can't any warmup tool fix?

Warmup builds trust in your inbox. It can't make people want an email they didn't expect. That's true of Warmuply, Warmup Inbox and every other warmup tool, and Warmup Inbox's own FAQ makes a similar point about needing good, personal email copy.

Three things only you control:

• Who you email. People who don't expect or want your email are the biggest risk. Old, bought or scraped lists also bring bounces and spam traps, which are addresses set up to catch senders using bad lists.
• Spam complaints. Every time someone clicks "Report spam", your reputation drops, and a well-warmed inbox can still end up in spam. Google's sender guidelines say to keep your spam rate in Postmaster Tools (Google's free dashboard showing how Gmail sees your domain) below 0.10%, and never let it reach 0.30% or higher.
• What your email says. A single word rarely sends an email to spam on its own. Spammy wording matters mostly because it makes people hit "Report spam".

What helps:

1. Email people who expect to hear from you, or who would reasonably welcome the email.
2. Write it like a one-to-one email, not an ad.
3. Keep links to one or two, and skip attachments.
4. Give people an easy way to opt out, and stop emailing anyone who asks.

For more on wording and complaints, read our guide to spam trigger words and what really sends a mail merge to spam.

How to decide between them

Both tools offer a 7-day free trial with no credit card, so you can try either one without risk. Run the trial on the exact address you'll send your mail merge from, and check two things: whether you understand what the tool is telling you, and whether it fits how you already send.

If you'd like to compare more options, see our guide to the best email warmup tools for mail merge senders.

Before you hit send

• Check your SPF, DKIM and DMARC with our free domain checker, and fix anything flagged before your mail merge goes out.
• Make sure everyone on your list expects to hear from you, and include an easy way to opt out.
• Keep today's send at or below a safe number for your inbox, not Google's daily maximum.
• Warming one Google Workspace address for a mail merge? Start a free 7-day trial of Warmuply. No credit card needed.