Email Warm-upEmail Warm-Up Tools for Agencies: Pricing, Pools and Providers
For agencies, compare email warm-up tools by mailbox economics first: this dataset runs from $0 per account to $69 per month, and several tools bill per inbox. Ignore the billing unit and a 20-client setup can become expensive or hard to explain. This guide compares price, pool type, provider coverage, Outlook support and reporting needs.
If you are choosing between client-only and shared warm-up, read the guide to private warm-up pools vs public networks before you sign a client. For one implementation that offers both models, the free warm-up tool and warm-up strategy page show the ramp, caps and readiness rules.
How should agencies shortlist tools?
This is a buying shortlist for agencies managing multiple client mailboxes. It is not a popularity ranking.
Competitor facts come from vendor pricing pages read on 3 October 2026. Prices change, so check before you buy. Where a fact was not visible in the supplied pricing-page data, this article says “not stated on their pricing page.”
Use these constraints first:
- Does the client require Outlook or Microsoft 365?
- Do you need a private pool for each client?
- Do you pay per inbox, per plan, or per outreach account?
- Is there a permanent free plan, or only a trial?
- Can the tool show mailbox-level readiness and spam placement?
Reporting depth was not consistently stated on competitor pricing pages. Before you commit, ask each vendor for mailbox-level spam placement, domain authentication checks, exports and per-client grouping.
Which email warm up tools for agencies fit?
Use this table to remove tools that miss a hard requirement. If Outlook is required, BobWork is not a fit today. If a permanent free plan is required, the paid competitors here do not state one.
| Tool | Free plan / trial | Cheapest paid | Cheapest-plan volume | Pool type | Providers listed | Outlook |
|---|---|---|---|---|---|---|
| BobWork Email Warm-up | Permanent free plan, no card, no time limit; up to 20 mailboxes per account; one mailbox is enough in the shared network, two or more for a private pool | $0 | Ramp 3→30/day per mailbox; cap editable up to 100 | Shared network, or private pool per account (your choice) | Gmail/Workspace, Zoho, Lark, Yahoo, iCloud, Amazon SES, SendGrid, Mailgun, any IMAP+SMTP | Not yet |
| Warmup Inbox | 7-day trial, no card; no free plan | $19/mo monthly, $15/mo annual, per inbox | 75 warm-up messages/day; replies up to 25%. Pro: 250/day. Max: 1,000/day | Shared network, “30,000+ real human inboxes” | Gmail, Workspace, Outlook, Microsoft 365, Yahoo, Zoho, ProtonMail, Fastmail, iCloud, AWS SES, Mailgun, any SMTP | Yes |
| MailReach | Trial not stated; no free plan | $19.50/mailbox/mo monthly, −20% annual | Up to 100 warming emails/day | MailReach network of Workspace/O365 inboxes, “30k+” | Any SMTP: Gmail/Workspace, Outlook/O365, Zoho, Brevo, Mailjet, Mailgun, SendGrid, SES, Sparkpost, Ionos, OVH | Yes |
| Lemwarm | Standalone trial not stated; lemlist offers 14 days no card and bundles lemwarm; no free plan | $29/mo monthly, $24/mo annual, per email address | Not stated on pricing page | Shared, “20,000+ real domains in 100+ countries” | Gmail, Outlook one-click; Zoho, FastMail, Proton mentioned; SMTP | Yes |
| Instantly | “Start free”, no card; length not stated; no free plan | $47/mo Growth outreach plan; warm-up bundled | Not stated per mailbox | Pool of Instantly customer accounts, “1,000,000+” | Google Workspace, Microsoft Outlook | Yes |
| Warmy | 7-day trial, no card; no free plan | From $49/month | Not stated on pricing page | Shared, “1M+ real mailboxes” | “Any ESP”, 35+ listed, including Gmail, Outlook, Zoho, SES, Mailgun, SendGrid | Yes |
| Mailwarm | No traditional free trial; no free plan | $69/mo Starter | Up to 50 warm-up emails + 50 replies/day. Growth: 200/day. Scale: 500/day | Mailwarm-operated pool, “50,000+ aged real inboxes” | Google Workspace/Gmail, Microsoft 365/Outlook, other SMTP platforms including Yahoo, Zoho, AWS, SendGrid, Mailgun | Yes |
The main split is clear. BobWork is the only permanent free plan in this dataset, and the only one listed that lets you choose between a shared network and a private pool per account. Every listed paid competitor states Outlook support; BobWork does not yet.
What changes at mailbox count?
Per-inbox pricing is easy to explain when every client has the same number of mailboxes. It gets harder when one client has 12 sales reps and another has two founders.
Per-plan or account-level pricing can be more predictable at higher mailbox counts. That only helps if provider coverage, reporting and client separation fit. Do not buy only on headline price.
Check these buying factors before you onboard clients:
| Buying factor | Agency risk | What to check |
|---|---|---|
| Billing unit | Costs rise faster than expected | Per inbox, per plan, per account, or bundled outreach account |
| Warm-up volume | Too much activity too soon | Daily cap, ramp speed and whether unknown limits require vendor confirmation |
| Pool type | Client data is harder to explain | Private pool or shared network |
| Provider coverage | Some clients cannot connect | Gmail, Workspace, Outlook, Zoho, Yahoo, iCloud, SES, SendGrid, Mailgun, IMAP/SMTP |
| Outlook | Microsoft clients are blocked | OAuth-based Outlook support |
| Reporting | Weak client updates | Spam placement, days warmed, authentication status and mailbox health |
| Authentication | Warm-up hides setup issues | SPF, DKIM and DMARC status |
| Sending guidance | Clients over-send after warm-up | Recommended real outreach volume per mailbox |
Provider rules matter more than any warm-up dashboard. Google’s sender guidelines tell bulk senders to authenticate with SPF, DKIM and DMARC, and to keep spam complaint rates low, ideally below 0.1% and never at or above 0.3%. Yahoo publishes sender requirements and best practices. Microsoft documents consumer sender guidance.
A client with broken SPF, missing DKIM or aggressive sending can still land in spam. Warm-up does not override provider filtering.
Which constraint decides the tool?
If you manage Gmail, Google Workspace, Zoho, Yahoo, iCloud, SES, SendGrid, Mailgun or IMAP+SMTP mailboxes, and clients do not need Outlook, BobWork is the lowest-cost option in this dataset. It is permanently free, and each account can choose a shared network or a private pool.
By default a BobWork account’s mailboxes warm in the shared network with other users’ active mailboxes. Switch an account to Private pool in the dashboard and its mailboxes write only to each other, so nobody else’s inbox receives the client’s addresses. You can use one account per client when you need strict separation. The account limit is up to 20 mailboxes; a private pool needs at least two.
BobWork has real limits. Outlook and Microsoft 365 are not supported yet because Microsoft requires OAuth. Gmail and Google Workspace users may see Google’s unverified-app notice because BobWork has not done the CASA audit.
The BobWork engine starts at 3 emails per day, adds 2 per day, and caps at 30 per day unless edited per mailbox. The maximum editable cap is 100. Weekends run at 30%, and sends are spread from 09:00 to 18:00 in the mailbox’s own time zone. The free pool does this step automatically for connected mailboxes.
Reporting includes a 7-day spam rate, a 0–100 health score, ready-for-outbound status, and daily SPF, DKIM and DMARC checks. BobWork touches only warm-up mail carrying its own hidden header, or a known subject for Zoho API senders. Real mail is never read, moved or answered.
If Outlook or Microsoft 365 is mandatory, shortlist tools that state Outlook support: Warmup Inbox, MailReach, Lemwarm, Instantly, Warmy or Mailwarm. Compare them on billing unit, stated daily volume and whether the shared pool is acceptable to your client.
If you already need an outreach platform, Instantly belongs in a different category from standalone warm-up tools. Its warm-up is bundled with the Growth outreach plan, so compare the full platform cost, not only warm-up.
If you are comparing specifically against Mailwarm, use the Mailwarm alternatives guide for a deeper vendor-by-vendor view.
What should agencies report?
A useful client report should show whether the mailbox is ready, what changed and what to do next.
Start with domain authentication. Show SPF, DKIM and DMARC per domain. If DKIM is missing, do not hide that behind warm-up activity. You can check records with the SPF checker, DKIM checker and DMARC checker.
Then show mailbox activity. Include days warmed, warm-up sent, warm-up received, replies, spam landings and current cap. If your vendor cannot show measured spam placement, ask how its health score is calculated.
Next show readiness. For BobWork, ready for outbound means 14+ days warming, a 7-day spam rate of 3% or lower, and at least 30 warm-up emails received. A mailbox should be paused for a few days above a 5% spam rate.
Finally show risk. Real outreach should typically stay around 30–50 emails per mailbox per day. Add mailboxes rather than forcing one sender. During campaigns, keep warm-up around 10–15 per day per mailbox unless your tool and client situation justify another setting.
For new domains, plan three to four weeks before meaningful outreach. For existing domains with clean history, 14 days is a practical minimum. The day-by-day warm-up timeline explains what to expect.
Run this agency checklist
Use this before you connect any client mailbox. It prevents two common failures: buying the wrong pricing model and warming a mailbox with broken domain setup.
| Step | Action | How to verify |
|---|---|---|
| 1 | Count mailboxes by client and provider | Make a sheet with client, domain, provider, mailbox count and sender role |
| 2 | Remove tools that miss a hard provider requirement | If Outlook is required, exclude tools without Outlook support |
| 3 | Calculate monthly cost | Multiply by the billing unit: per inbox, per plan, per account, or outreach platform |
| 4 | Decide pool policy | Mark each client “private required” or “shared acceptable” |
| 5 | Check SPF, DKIM and DMARC | Inspect DNS records before warm-up starts |
| 6 | Confirm ramp and cap | Ask the vendor or inspect settings; avoid sudden high volume on new domains |
| 7 | Define readiness | Use days warmed, received volume and measured spam placement |
| 8 | Set campaign limits | Keep real outreach typically at 30–50 per mailbox per day |
| 9 | Build the client report | Include authentication, activity, spam rate, health and next action |
| 10 | Recheck after launch | Watch spam placement and complaints after real campaigns start |
If you want to test either model before paying for anything, start with BobWork Email Warm-up. Connect your supported mailboxes (two or more if you switch the account to a private pool), check authentication, let the ramp run, and judge readiness from measured spam placement rather than promises.
Frequently asked questions
What is the best email warm-up tool for agencies?
The best tool depends on your constraints. If you need a permanent free plan with the choice of a shared network or a private pool per client, BobWork fits. If you need Outlook today, use a tool that lists Outlook support, such as Warmup Inbox, Mailwarm, Lemwarm, Warmy, Instantly or MailReach.
Should agencies use shared warm-up pools?
Shared pools can be convenient, but they mix your mailbox with strangers’ inboxes. For client work, a private pool is easier to explain and control. If you use a shared pool, ask how peers are chosen and what happens if a peer account behaves badly.
How many mailboxes does an agency need to warm up?
Warm up every sending mailbox you plan to use. If you manage several clients, separate them by domain, provider and campaign. Add mailboxes rather than pushing one mailbox too hard.
How long should agencies warm up client mailboxes?
Typically use at least 14 days for an existing domain and 3–4 weeks for a new domain. Keep watching spam placement after launch. Warm-up does not replace SPF, DKIM, DMARC, list quality or restrained sending volume.
What should an agency report to clients?
Report mailbox status, SPF, DKIM, DMARC, warm-up volume, 7-day spam rate, days warmed, and whether the mailbox is ready for outbound. Avoid vague inbox placement claims unless you can show how you measured them.
Can email warm-up guarantee inbox placement?
No. Warm-up can create normal mailbox activity and show placement signals, but inbox placement also depends on authentication, domain history, content, sending volume, complaints and recipient engagement.
Is Outlook supported by all warm-up tools?
In this comparison, all listed paid competitors state Outlook support. BobWork does not support Outlook yet because Microsoft requires OAuth. Check the vendor’s current provider list before you buy.
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.