Email Warm-upBest Free Email Warm-Up Tool in 2026: Verified Free Plans Compared
Among standalone warm-up tools, only TrulyInbox (1 account, 10 emails/day) and BobWork Email Warm-up (up to 20 mailboxes, 3–30 emails/day each) offer a free-forever plan in the verified 2026 table. If you mistake a short trial for free warm-up, it can end before a mailbox is ready. This comparison separates free-forever, trial-only and paid options with stated limits.
If you want setup instructions, read our free email warm-up guide after this comparison. This page is only about the tools, public limits, pool models, and trade-offs you can verify before signing up.
How did we compare them?
We checked each vendor’s own pricing page and used only facts stated there. Free-tier facts were verified on 4 October 2026. Broader paid-pricing facts used in our alternatives coverage were read on 3 October 2026. Prices change, so check the vendor’s page before you buy.
We sorted tools into three groups:
- Free-forever warm-up plans with stated warm-up limits.
- Trial-only tools where free access ends.
- Paid-only, unclear, or not-verified-as-free warm-up options.
We did not score tools by design, brand size, testimonials, or claims we could not verify. When a limit was not stated on the pricing page, the table says “n/s on pricing page.”
Pool type matters as much as price. A private pool means your own mailboxes exchange warm-up mail with each other. A shared pool means your mailbox exchanges mail with other users, vendor-operated inboxes, or a peer network. If that choice matters to you, read our guide to private warm-up pools vs public networks.
Which tools are actually free?
Among standalone warm-up tools, only TrulyInbox and BobWork Email Warm-up have a verified free-forever warm-up plan in this table. Every other listed product is trial-only, paid-only, bundled, or unclear for free warm-up volume.
| Tool | Free plan | Free warm-up limit | Cheapest paid | Pool type | Outlook |
|---|---|---|---|---|---|
| BobWork Email Warm-up | Yes, free forever | Up to 20 mailboxes; 3/day ramping to 30/day each; cap editable to 100 | $0 | Shared network, or private pool per account (your choice) | Not yet |
| TrulyInbox | Yes, free forever | 1 email account; 10 warm-up emails/day; basic deliverability tracking; no card | Starter $22/mo annual, $29 monthly | Peer network of 40,000+ real accounts | Yes |
| Warmup Inbox | No, trial only | Full plan access during trial; mailbox limit n/s | Basic $15/inbox/mo annual, $19 monthly | Vendor-run 30,000+ real inboxes | Yes |
| Instantly | No free plan | Trial: 250 contacts, 1,000 emails, warm-up from day one; account deleted if not upgraded | Growth $47/mo | Customers’ accounts, 4.2M+ | n/s on pricing page |
| Smartlead | No, trial only | Trial: 2,500 sends, 1,250 contacts | Base $39/mo | Private, reward-based, limited-access network | Yes |
| InboxAlly | No, trial only | Trial limits n/s | Starter $149/mo, 100 seed emails/day | Vendor-run US seed network | Yes |
| Warmy | No, trial only | Free limits n/s | From $49/mo | Shared, over 1 million mailboxes | Yes |
| Mailivery | No, trial only | Free limits n/s | Starter $29/mo | Peer-to-peer between customers | Yes |
| Warmbox | No, trial only | Free limits n/s | Solo $15/mo yearly, $19 monthly | Vendor-run 35,000+ private inboxes | Yes |
| Folderly | Warm-up not free | Free = alerts plus 2 tests/month | Warm-up $96/mailbox/mo | n/s on pricing page | n/s on pricing page |
| Lemwarm | No standalone free plan | Free warm-up limits n/s; lemlist seats include it | Essential $24/mo annual, $29 monthly | Shared 20,000+ domains | Yes |
| MailReach | No free plan | Free spam test only, 3 per 24h | $19.50/mailbox/mo | Vendor-run Workspace/O365 inboxes, 30k+ | Yes |
| Mails.ai | Free tier exists, but warm-up volume n/s | Pricing page now sells agent-email API: 1 agent, 3,000 events/month, no card | Pro $20/mo | Vendor-run shared pool | Blog says paid only |
The table supports only two free-forever picks for warm-up: BobWork and TrulyInbox. BobWork has the larger stated free capacity. TrulyInbox has Outlook support and a smaller free limit.
Provider coverage still matters. BobWork supports Gmail/Workspace, Zoho, Lark, Yahoo, iCloud, SES, SendGrid, Mailgun, and any IMAP+SMTP mailbox, but not Outlook yet. TrulyInbox states Outlook support. Several trial-only and paid tools also support Outlook.
What is the best free email warm up tool?
The best free email warm up tool depends on your constraint. If you need the largest verified free warm-up capacity, BobWork is first because it allows up to 20 mailboxes and ramps each one from 3 to 30 emails/day. If you need Outlook support in a free-forever plan, TrulyInbox is the verified free option in this table that states Outlook support.
That is not a brand ranking. It follows from the stated free limits and provider support.
BobWork has limits. A private pool needs at least two mailboxes, though one is enough in the shared network. Outlook and Microsoft 365 are not supported yet. Gmail and Google Workspace can connect with Google sign-in, but Google shows an unverified-app notice because we have not done the CASA audit.
TrulyInbox has a smaller free limit. Its verified pricing page states 1 email account and 10 warm-up emails/day. That can suit one new sender. It is not enough if you need to warm several mailboxes under one account.
If you are new to warm-up, read what happens during the first warm-up before you connect anything. It explains why the first days are slow and why a short trial can expire before you have enough signal.
Which free plan fits you?
Use BobWork Email Warm-up if you do not need Outlook yet and want a free shared network, or a private pool for two or more of your own mailboxes. It is free forever, with no card, no time limit, and up to 20 mailboxes per account.
By default your mailboxes warm with other users’ active mailboxes in the shared network; switch the account to Private pool and only your own mailboxes write to each other. The engine starts at 3 emails/day, adds 2 per day, and caps at 30/day by default. You can edit the cap per mailbox up to 100, though lower volume is safer during real outreach.
BobWork supports Gmail and Google Workspace, Zoho Mail, Lark Mail, Yahoo Mail, iCloud Mail, Amazon SES, SendGrid, Mailgun, and any IMAP+SMTP mailbox. For Gmail, you can use Google sign-in or IMAP with an app password. Google sign-in asks for gmail.modify and shows the unverified-app notice.
The free pool does the routine warm-up actions automatically. Warm-up mail found in Spam is moved to Inbox, marked read, labelled “Warm-up,” and archived after 24 hours. It only touches mail carrying the engine’s hidden header, or a known subject for Zoho API senders.
Use TrulyInbox if you need one free mailbox and Outlook support. Its free plan is listed as 1 email account, 10 warm-up emails/day, basic deliverability tracking, and no card.
TrulyInbox uses a peer network. The pricing page states 40,000+ real accounts, including Google, Microsoft, and Zoho counts. If you prefer not to exchange warm-up mail with other customers, switch BobWork to its private-pool mode instead.
Which tools are trials?
Warmup Inbox has no free plan. It offers a 7-day no-card trial, and Basic is $15/inbox/month annually or $19 monthly. Basic states 75 warm-up messages/day. The trial gives full plan access, but the mailbox limit during trial was not stated on the pricing page.
Instantly has no free plan. Its trial lists 250 contacts, 1,000 emails, and warm-up from day one. Growth is $47/month. Treat it as an outreach-platform trial, not a permanent warm-up account. The pricing page says trial accounts are deleted if not upgraded.
Smartlead has no free plan. Its trial lists 2,500 sends and 1,250 contacts, with Base at $39/month. It suits teams evaluating cold email software rather than only warm-up. The pricing page states unlimited accounts and bundled warm-up.
InboxAlly has no free plan. It offers a 10-day no-card trial, and Starter is $149/month for 100 seed emails/day. It suits buyers comparing seed-based placement tools. Free trial limits were not stated on the pricing page.
Warmy has no free plan. It offers a 7-day no-card trial, and pricing starts from $49/month. The pricing page lists any ESP and 35+ providers, including Gmail, Outlook, Zoho, SES, Mailgun, and SendGrid. Daily free limits were not stated.
Mailivery has no free plan. It offers a 7-day trial, and Starter is $29/month. It uses peer-to-peer warm-up between customers. The pricing page lists Outlook support. Free limits and provider coverage were not stated on the pricing page.
Warmbox has no free plan. It is trial-only, and Solo is $15/month yearly or $19 monthly. The pricing page states 35,000+ private inboxes. Trial length and free limits were not stated, but no-card trial access was stated.
Folderly’s free offer is alerts plus 2 tests/month. Warm-up is not free and costs $96/mailbox/month. Pool type, provider coverage, and Outlook support were not stated on the pricing page.
Which tools are paid or unclear?
Lemwarm has no standalone free plan. Lemlist seats include it, and Essential is $24/month annually or $29 monthly per email account. Trial information was conflicting: one help page mentioned 14 days, while another said lemwarm is not in the lemlist trial. Treat free standalone warm-up as not available.
MailReach has no free plan and no trial. It offers a free spam test limited to 3 per 24 hours. The pricing page states $19.50/mailbox/month and up to 100 warming emails/day. It supports any SMTP, including Gmail/Workspace, Outlook/O365, Zoho, Mailgun, SendGrid, and SES.
Mails.ai has a free tier, but the pricing page now sells an agent-email API and does not state warm-up volume. For free warm-up, the verified table does not provide a usable warm-up limit. Its blog says paid only, so do not treat it as a verified free warm-up tool.
What can’t free warm-up fix?
Warm-up is not a bypass for poor sending practice. It can create normal mailbox activity, produce replies, and reveal whether warm-up mail lands in Spam. It cannot make bad lists safe, hide complaints, or repair broken authentication by itself.
Google tells senders to keep spam complaint rates under 0.1% and avoid ever reaching 0.3% in its Email sender guidelines. Yahoo publishes sender expectations in its sender best practices. These are operating limits for real outbound mail, not warm-up tool settings.
Free warm-up also does not replace SPF, DKIM, and DMARC. Use an SPF checker, DKIM checker, and DMARC checker before you send campaigns. If your records are wrong, warm-up activity gives you noise instead of signal.
It does not fix a new domain overnight. A typical practice is 14 days for an existing domain and 3–4 weeks for a new domain. During campaigns, keep warm-up at 10–15/day and real outreach around 30–50/day per mailbox. Add mailboxes rather than pushing one inbox harder.
It also does not make short trials equal to permanent tools. A 7-day trial may end before a new domain has enough history. Read our day-by-day warm-up timeline if you are planning a launch date.
What should you do now?
Use this checklist before you connect a mailbox. It prevents most wrong-tool choices.
| Step | Action | How to verify |
|---|---|---|
| 1 | Decide whether you need free forever or only a trial | Check the pricing page for the exact words “free forever,” “trial,” or “no free plan” |
| 2 | Count mailboxes you need to warm | Compare your count with the free limit, not the paid plan limit |
| 3 | Check provider support | Confirm Gmail, Workspace, Zoho, Outlook, SES, SendGrid, Mailgun, or IMAP support |
| 4 | Choose pool type | Look for private pool, peer network, shared pool, seed network, or vendor-run inboxes |
| 5 | Check authentication | Verify SPF, DKIM, and DMARC before warm-up starts |
| 6 | Start below campaign volume | Keep real outreach around 30–50/day per mailbox once ready |
| 7 | Watch spam placement | Pause a mailbox for a few days if its 7-day spam rate rises above 5% |
If you choose BobWork, the engine behaviour is published here: ramp from 3/day, add 2/day, default cap 30/day, weekends at 30%, and sends spread across 09:00–18:00 in each mailbox’s time zone. A mailbox is ready for outbound after 14+ days warming, a 7-day spam rate of 3% or less, and at least 30 warm-up emails received.
The practical choice is narrow. Use BobWork if you want the largest verified free-forever capacity and do not need Outlook yet. Use TrulyInbox if you need one free mailbox with Outlook support. Use a trial-only or paid tool when its provider coverage, network type, or bundled outreach platform is worth paying for. You can start with BobWork Email Warm-up without a card, then switch later if Outlook support becomes your deciding factor.
Frequently asked questions
What is the best free email warm-up tool in 2026?
By verified free capacity, BobWork offers up to 20 mailboxes at 3–30 emails per day each. TrulyInbox also has a free-forever plan, but it is listed as 1 email account and 10 warm-up emails per day.
Are there many free-forever email warm-up tools?
No. In the verified table, only TrulyInbox and BobWork Email Warm-up offer free-forever warm-up plans. Most other tools are paid products with a short trial or no trial.
Is a free trial the same as a free warm-up plan?
No. A trial usually ends after 7, 10 or 14 days. A free-forever plan keeps working after the trial period would end, subject to its stated limits.
Does email warm-up guarantee inbox placement?
No. Warm-up can build sending activity and reveal spam placement, but it does not guarantee inbox placement. Authentication, list quality, complaints, content and sending volume still matter.
Can I warm up Outlook or Microsoft 365 for free?
BobWork does not support Outlook yet because Microsoft requires OAuth. TrulyInbox lists Outlook support. Several paid or trial-only tools also list Outlook support on their pricing pages.
How long should I warm up a mailbox?
A typical starting point is 14 days for an existing domain and 3–4 weeks for a new domain. Keep real outreach low while the mailbox builds stable engagement.
What should I check before choosing a tool?
Check whether the free plan is permanent, how many mailboxes it allows, daily warm-up volume, pool type, provider support, Outlook support, and whether limits are stated on the pricing page.
Warm up your mailboxes free
Connect Gmail, Google Workspace, Zoho or Lark. Your mailboxes warm on a shared network, or in a private pool of your own, starting today.