Cheapest Email Warm-Up Tool in 2026: Free and Paid Prices Compared

The cheapest email warm-up tool in this comparison is BobWork Email Warm-up at $0 for up to 20 mailboxes. If you compare only headline prices, you can miss Outlook support, shared-pool trade-offs and daily volume limits. This guide compares monthly cost for 1, 5 and 20 mailboxes, then shows what each price includes.

How did we compare prices?

We compared seven warm-up tools using their own pricing pages, read on 3 October 2026. Prices change, so check each vendor’s pricing page before you buy.

The tools are BobWork Email Warm-up, Warmup Inbox, Mailwarm, Lemwarm, Warmy, Instantly and MailReach. We used only stated pricing, free-plan, provider, Outlook and pool-type facts from those pages.

For more context on free options, see our guide to the best free email warm-up tools. If you are still deciding whether warm-up fits your situation, start with what to expect when warming up for the first time.

The comparison rules:

• Monthly cost means the cheapest listed monthly price, not annual prepayment.
• Annual discounts are mentioned separately.
• Per-mailbox tools are multiplied by mailbox count.
• Plan-based tools use the lowest listed plan that covers the mailbox count.
• If the pricing page does not state a number, the table says so.
• If 20 mailboxes are not clearly covered, we do not assume coverage.

Price is not the only constraint. Pool type matters because a private pool uses only your own mailboxes. A shared pool exchanges mail with other users’ mailboxes. Provider support also matters, especially for Outlook and Microsoft 365.

What is the cheapest email warm-up tool?

BobWork Email Warm-up is the only permanent free plan in this comparison. It is free, requires no credit card and supports up to 20 mailboxes per account. One mailbox is enough to start in the shared network; a private pool needs at least two.

Every paid competitor listed supports Outlook. BobWork does not support Outlook yet because Microsoft requires OAuth.

The main trade-off is clear. Free can be enough if you have supported non-Outlook mailboxes; you get a shared network by default and can switch to a private pool. Paid tools make more sense when you need Outlook support, bundled outreach features or vendor-managed peers.

What does each mailbox count cost?

This table compares estimated monthly cost for 1, 5 and 20 mailboxes. It uses monthly billing where stated. Annual discounts appear in the notes, not as the default price.

For one paid mailbox, Warmup Inbox has the lowest listed monthly paid price at $19 per inbox. MailReach is close at $19.50 per mailbox per month.

For five paid mailboxes, Instantly’s $47 account price is lower than per-mailbox warm-up tools. But it is an outreach platform plan, and daily warm-up volume per mailbox is not stated. For standalone per-mailbox warm-up, Warmup Inbox and MailReach remain the lowest listed paid options.

For 20 mailboxes, BobWork stays free within its account limit. Among paid tools, Instantly lists unlimited email accounts on the $47 Growth plan, but daily warm-up volume per mailbox is not stated. Warmup Inbox, MailReach and Lemwarm scale directly by mailbox count.

Do not compare only dollars. A $0 tool and a paid network can solve the same problem; check what each includes. A bundled outreach platform also differs from a standalone warm-up tool.

What does each price include?

BobWork Email Warm-up: BobWork is $0 per account, with up to 20 mailboxes and a default ramp from 3 to 30 emails per day per mailbox. It suits teams with supported mailboxes that want a shared network, or a private pool if they control two or more.

BobWork supports Gmail and Google Workspace, Zoho, Lark, Yahoo, iCloud, Amazon SES, SendGrid, Mailgun and any IMAP+SMTP mailbox. The limits are clear: no Outlook yet, a private pool needs at least two mailboxes, and Google users may see an unverified-app notice because the CASA audit has not been completed.

By default your mailboxes warm in the shared network with other users’ active mailboxes; switch the account to Private pool and only your own mailboxes write to each other. The free pool handles sending, replies, spam rescue for its own warm-up mail and daily SPF, DKIM and DMARC checks. See the warm-up engine behaviour for the ramp details.

Warmup Inbox: Warmup Inbox starts at $19 per inbox per month on monthly billing, or $15 per inbox per month on annual billing. It suits buyers who want a paid shared network with broad provider coverage and Outlook support.

The Basic plan lists 75 warm-up messages per day and replies up to 25%. The trade-off is cost growth by inbox count: five inboxes cost $95 per month on monthly billing, and 20 cost $380.

Warmup Inbox also lists a 7-day trial with no card. It does not list a permanent free plan.

Mailwarm: Mailwarm starts at $69 per month for Starter. Starter covers 1 mailbox with up to 50 warm-up emails and 50 replies per day.

It suits buyers who want a Mailwarm-operated pool and plan-based pricing. Growth is $159 for 3 mailboxes, and Scale is $479 for 10 mailboxes. The pricing page does not clearly state a 20-mailbox price.

Mailwarm lists Google Workspace/Gmail, Microsoft 365/Outlook and other SMTP platforms. It names Yahoo, Zoho, AWS, SendGrid and Mailgun. Its entry price is higher than the lowest per-mailbox paid tools for one mailbox.

Lemwarm: Lemwarm starts at $29 per month per email address, or $24 per month per email address on annual billing. It suits users who want warm-up tied to the lemlist ecosystem or a shared network with Gmail and Outlook one-click support.

The pricing facts list a shared network with “20,000+ real domains in 100+ countries.” Daily warm-up volume on the cheapest plan is not stated on the pricing page.

Cost planning is simple because Lemwarm is priced per email address. Five mailboxes cost $145 per month on monthly billing. Twenty mailboxes cost $580 per month.

Warmy: Warmy pricing is listed as “from $49/month,” with a 7-day trial and no card. It suits buyers who want a shared pool and broad ESP coverage.

The pricing facts list “any ESP” and 35+ providers, including Gmail, Outlook, Zoho, SES, Mailgun and SendGrid. The limits: tier prices are not readable on the page, and daily warm-up volume on the cheapest tier is not stated.

Because pricing is volume-based, confirm the exact tier for your mailbox count. Do not assume five or 20 mailboxes are covered at the entry price unless the vendor confirms it.

Instantly: Instantly starts at $47 per month for the Growth outreach plan, with unlimited email accounts and unlimited warm-up stated. It suits teams that want warm-up bundled with an outreach platform rather than a standalone warmer.

The listed providers are Google Workspace and Microsoft Outlook. Daily warm-up volume per mailbox is not stated.

Instantly becomes cost-attractive in this table as mailbox count rises because the billing unit is the account, not the mailbox. That depends on the pricing page’s “unlimited email accounts” wording. Still check sending limits, warm-up behaviour and fit with your outreach workflow.

MailReach: MailReach starts at $19.50 per mailbox per month on monthly billing, with 20% off annual billing. It suits buyers who want a paid per-mailbox warmer with Outlook/O365 support and any-SMTP coverage.

MailReach lists up to 100 warming emails per day. It uses a MailReach network of Workspace and O365 inboxes.

Pricing is straightforward. One mailbox costs $19.50 per month, five cost $97.50, and 20 cost $390 on monthly billing. Cost rises with every added mailbox.

When is free warm-up enough?

Free warm-up is enough when the free plan covers your real constraints. For BobWork, that means you use supported providers and do not need Outlook yet.

It also fits teams that prefer private warm-up: switch the account to Private pool and your mailboxes exchange warm-up messages without involving strangers’ inboxes, which can suit privacy-sensitive domains.

Free is less suitable when you want a private pool but only have one mailbox. Warm-up needs peers, so a private pool requires at least two mailboxes; in the shared network one is enough.

Free is also less suitable when you want vendor-provided network volume. Shared networks can give you more external peers. The trade-off is that your mailbox participates with other customers’ mailboxes.

You still need correct authentication. SPF, DKIM and DMARC should pass before you scale. Use our free SPF checker, DKIM checker and DMARC checker for a quick DNS check.

Watch complaint signals too. Google’s sender guidance says to keep spam complaint rates below 0.1% and avoid reaching 0.3%; see Google’s email sender guidelines. Yahoo publishes sender requirements in its sender best practices.

When should you pay?

Pay when a paid tool covers a constraint that free warm-up does not. The clearest example is Outlook. Every paid competitor in this comparison lists Outlook support. BobWork does not support Outlook yet because Microsoft requires OAuth.

Pay when you want a vendor-operated network with Outlook support. Warmup Inbox, Mailwarm, Lemwarm, Warmy, Instantly and MailReach all use shared pools or networks, according to the pricing facts. BobWork’s shared network is free, so pay only when a paid network offers something it does not.

Pay when you want higher stated warm-up volume. Warmup Inbox lists 75 warm-up messages per day on Basic. MailReach lists up to 100 warming emails per day. Mailwarm lists up to 50 warm-up emails and 50 replies per day on Starter.

Pay when warm-up is bundled with another tool you already need. Instantly is priced as an outreach platform plan with warm-up included. If you need that platform anyway, its account-level price may matter more than per-mailbox warm-up pricing.

Do not pay just because a tool is paid. Match the tool to mailbox count, provider, pool type and stated daily volume. Then compare price.

If your issue is current spam placement, warm-up alone may not fix it. Work through the causes in why emails go to spam before you add mailboxes or volume.

What should you check before buying?

Use this checklist before you choose a tool. It prevents two common mistakes: buying for the wrong provider and underestimating cost at 5 or 20 mailboxes.

For a conservative ramp, start with low daily volume and increase gradually. BobWork starts at 3 emails per day, adds 2 per day, and caps at 30 per day by default. Weekends run at 30% volume.

During campaigns, keep warm-up steady rather than extreme. We recommend 10–15 warm-up emails per day during active outreach. For real outreach, stay around 30–50 per mailbox per day and add mailboxes instead of forcing volume into one sender.

New domains need more patience. Use about 14 days for an existing domain and 3–4 weeks for a new one. Our day-by-day warm-up timeline shows what to expect.

Choose by your hardest constraint. If monthly cost is the constraint, BobWork is cheapest because it is free up to 20 mailboxes. If you need the lowest paid standalone mailbox, Warmup Inbox is lowest at $19 per inbox per month, followed by MailReach at $19.50.

If you need 20 paid mailboxes, Instantly’s $47 Growth plan looks cheapest among paid options because it states unlimited email accounts and unlimited warm-up. But it is an outreach platform plan, and daily warm-up volume per mailbox is not stated.

If privacy is the constraint, compare pool type first. A private pool keeps warm-up inside your own mailboxes. A shared pool gives you external peers but involves other users’ inboxes.

You can try BobWork Email Warm-up without a card if your mailboxes fit the limits. Connect your supported mailboxes, check your domain records and let the ramp run before you increase real outreach.

Frequently asked questions