Email Warmup Cost: Monthly Price at 1 to 1,000 Mailboxes

Email warmup cost ranges from $0 on a real free plan to about $15–$29 per mailbox per month on common standalone tools; at scale, BobWork is $120 for 50 mailboxes and $1,980 for 1,000. If you price only the first inbox, warm-up becomes a hidden fleet bill. This guide shows the monthly math and buying checks.

The mistake is treating warm-up as a one-inbox purchase. Cold email teams buy domains, add mailboxes, and then discover the warm-up bill later. Use the full fleet count before you connect anything. For a narrow per-mailbox view, compare this with our cheapest email warm-up per mailbox guide.

Prices below are monthly unless stated otherwise. BobWork prices are current product facts. Competitor prices were read from the vendors’ own pricing pages on 3 October 2026, with noted re-checks on 27 October 2026 where available. Check the vendor page before you buy.

What is the email warmup cost?

At one mailbox, the market looks cheap. At 50 mailboxes, the pricing model matters more than the headline price.

There are four common pricing patterns.

Free-forever plans are useful only when they are not short trials. In our verified standalone set, BobWork and TrulyInbox have free-forever plans with daily warm-up. Warmup Inbox also lists a freemium plan, but the free limit is 15 warm-up emails per week.

Per-mailbox pricing is easy to understand and easy to underestimate. A $19 mailbox is $19 at one inbox. It is $950 at 50 mailboxes before annual discounts or custom terms.

Plan pricing works differently. Mailwarm lists plan tiers rather than a simple per-inbox price. Its Starter plan is $69 per month for one mailbox. Its Scale plan is $479 per month for 10 mailboxes.

Outreach-platform pricing bundles warm-up into a broader sending product. Tools such as Instantly, Woodpecker, Apollo, Mailshake, and QuickMail can be the right choice if you also need sequences, inbox rotation, contact data, or sales workflow features.

This post focuses on standalone warm-up cost. If you are choosing a sending platform, compare the campaign tool separately. Warm-up is only one line in that bill.

What does BobWork cost by mailbox?

BobWork Email Warm-up is free for up to 10 mailboxes on new accounts. There is no credit card and no time limit. Active mailboxes above 10 are billed by Stripe, prorated, and can be cancelled any time. Extra mailboxes pause without billing.

The free plan changed on 27 October 2026. New accounts get 10 free mailboxes. Early users who created accounts before that date keep 20 free mailboxes for as long as they use the service.

The paid ladder is simple at scale. Extra mailboxes are $5 each at small overages, $3 each once you have 10 extra, and $2 each once you have 50 extra. Referral and AppSumo extras stack on top.

The capacity column is not a recommendation for cold email volume. It is the default warm-up cap after ramping. Each mailbox starts at 3 warm-up emails per day, increases by 2 per day, and caps at 30 per day by default. The cap is editable per mailbox up to 100.

Weekends run at 30%. Sends are spread between 09:00 and 18:00 in the mailbox’s own time zone, with randomness. A pair of mailboxes will not write to each other twice within three hours.

Yearly billing is also live. Extra mailboxes can be paid yearly at 10 times the monthly price, which gives two months free. For example, 480 extra mailboxes cost $960 per month or $9,600 per year.

How do paid tools compare?

Do not compare only the cheapest first inbox. Compare the billing unit, free plan, stated daily volume, provider coverage, and what happens at 50 mailboxes.

The table below uses vendor pricing pages as the source. Pricing pages can change. Primary references: Warmup Inbox pricing, MailReach pricing, Mailwarm pricing, and TrulyInbox pricing.

This table is not saying the cheapest line is always best. It shows what you must match to the job.

Warmup Inbox and MailReach list higher daily warm-up volume on entry paid tiers than BobWork’s default 30 per mailbox. BobWork lets you edit the cap up to 100, but our published recommendation is to keep warm-up at 10–15 per day during active campaigns.

Mailwarm’s plan includes a stated reply count. BobWork replies to about 40% of received warm-up mail, and threads end after three messages.

Most competitors in this set support Outlook or Microsoft 365. BobWork does not support Outlook yet. If Outlook support is required today, that should decide the shortlist before price.

What changes at 50 mailboxes?

A 50-mailbox fleet is where pricing stops being a small subscription.

At 50 BobWork mailboxes on a new account, you pay $120 per month. At 50 Warmup Inbox Basic mailboxes at $19 monthly, simple multiplication gives $950. At 50 MailReach mailboxes at $19.50 monthly, it gives $975.

Those numbers do not include annual discounts, custom vendor offers, or bundled outreach features. They do show the shape of the decision. Per-mailbox tools can be fine for one to five inboxes. At agency or infrastructure scale, the billing model becomes part of the product.

You also need to think about domains. Sending 50 mailboxes from one domain is rarely sensible for cold email. Teams typically spread mailboxes across several domains. A common planning range is 2–5 mailboxes per domain, then add domains rather than forcing one domain harder.

Use our mailbox calculator guide before you buy seats. If you already know you need a larger fleet, the bulk email warm-up guide explains the operational side.

BobWork’s CSV bulk upload is live. In Add mailbox → Many mailboxes: upload a CSV, paste or upload rows of email, app_password, and name. Gmail, Yahoo, and iCloud hosts are filled in. Other domains add imap_host.

Each row gets the same IMAP and SMTP login test as a single connection. Failed rows are listed with the reason. Already-connected rows are skipped, so a re-upload is safe. Mailboxes above the free limit need billing active before they connect.

The default account limit is 200 mailboxes. Larger fleets, such as 500 or 1,000 mailboxes, can request a higher limit at info@bobwork.ai. For 50+ mailboxes, consider a private pool so only your account’s mailboxes warm each other.

Check volume before price

A warm-up price is meaningless without the ramp.

A mailbox that sends 100 warm-up emails on day one is not the same as a mailbox that ramps from 3 to 30. Warm-up should look like normal human sending, not a sudden synthetic burst.

BobWork’s engine starts each mailbox at 3 emails per day. It adds 2 per day and caps at 30 by default. During campaigns, our published recommendation is to keep warm-up at 10–15 per day. Real outreach should usually stay at 30–50 cold emails per day per mailbox.

That means 50 mailboxes should not tempt you into blasting from one domain. Add mailboxes to spread load. Add domains when the domain is the bottleneck. Keep the ramp separate for every mailbox.

The free shared warm-up network does this step automatically. Every active mailbox warms with other active mailboxes by default. If you prefer, switch to a private pool in Mailbox pool → Pool mode. A private pool needs at least two mailboxes.

Warm-up messages are short plain-text office notes. They have no links and no images. Users do not write the network text, so nobody can push spam or links through it. Only mail carrying the engine’s hidden header is touched.

Spam rescue is part of the volume calculation. Warm-up mail found in Spam is moved to Inbox, marked read, labelled Warm-up, and archived after 24 hours. Real mail is never read, moved, or answered.

If you want the exact engine behaviour before committing mailboxes, read the warm-up strategy page.

Watch hidden monthly costs

The warm-up subscription is only one cost. The mailbox provider, domains, DNS work, campaign tool, and list quality all affect the monthly total.

Start with the provider. BobWork supports Gmail and Google Workspace, Zoho Mail, Lark Mail, Yahoo Mail, iCloud Mail, Amazon SES, SendGrid, Mailgun, and any IMAP plus SMTP mailbox. Gmail and Google Workspace work best through IMAP with an app password, which requires 2-Step Verification.

One-click Google sign-in exists, but Google caps unverified apps at 100 users. BobWork has not done the CASA audit, so Google shows an unverified-app notice and spots are limited. A Workspace admin can mark the app as trusted in the Admin console.

Zoho Mail has two routes. The Zoho Mail API route works on the free Zoho plan through a Self Client code. IMAP works on Mail Lite and above. If Zoho is your provider, use the Zoho warm-up setup guide.

Outlook and Microsoft 365 are the exception. BobWork does not support them yet because Microsoft requires OAuth. If you need that provider, use an Outlook-ready tool. Our Outlook warm-up guide explains what works without password IMAP.

Next, check DNS. At minimum, you need SPF, DKIM, and DMARC. Google publishes a complaint-rate target below 0.1%, and says it should never reach 0.3% or higher. Yahoo requires SPF and DKIM, DMARC at least p=none and passing, alignment, one-click unsubscribe for bulk, and spam rate under 0.3%.

Warm-up cannot fix a broken domain. It can create engagement and measure spam placement, but SPF, DKIM, DMARC, list quality, and complaint control still decide whether real campaigns survive.

Finally, separate warm-up from sending software. BobWork has optional pay-as-you-go Outbound at $2 per 1,000 emails sent from your own warmed mailboxes. You do not need it for warm-up. If you already pay for another campaign tool, include that separate bill.

Do this now

Use this checklist before you buy or migrate warm-up tools.

Do not skip step three. The cheapest tool at one mailbox can be expensive at 50. The best outreach platform may be worth it if you need its campaign features. The cheapest warm-up tool may be better if you only need warming.

For free-plan comparisons, read free email warm-up tools in 2026. For large imports, use the CSV import guide.

Use a free standalone warm-up tool when you only need mailbox warm-up, spam placement checks, and DNS visibility. This fits Gmail, Google Workspace, Zoho, Yahoo, iCloud, SES, SendGrid, Mailgun, and other IMAP plus SMTP mailboxes.

Use a paid per-mailbox warm-up tool when you need a provider BobWork does not cover, especially Outlook or Microsoft 365, or when its stated daily volume and reporting match your workflow.

Use an outreach platform with bundled warm-up when you also need campaign sequences, inbox rotation, contact data, LinkedIn steps, or team sales workflows. Someone already paying for one of those platforms may not need a separate warm-up service.

Use private pool mode when you have enough of your own mailboxes and do not want any outside account involved. In BobWork, shared network is the default. Private pool is optional per account and needs at least two mailboxes.

If you want the lowest monthly number for supported providers, start with BobWork Email Warm-up. It is free for up to 10 mailboxes on new accounts, needs no credit card, and scales to large fleets with the price ladder shown above. Connect one mailbox to test, then bulk-upload once the setup is proven.

Frequently asked questions