Open sourceApache 2.0

The largest open-source cold email platform.

Warmbly warms up your mailboxes, sends your campaigns across them, and brings every reply into one inbox. Use our cloud or host it yourself.

14-day free trial · No credit card · Plans from $29 a month

Everything you need to run cold email.

Connect your mailboxes, warm them up, send campaigns and handle the replies, all from one dashboard.

One inbox for every reply

Replies from all your mailboxes arrive in one place, already labeled as interested, out of office, a question or an unsubscribe.

Emails that read as personal

Write each step with variables like first name and company, test two versions against each other, and draft or rewrite with AI.

A pipeline for your deals

Move interested leads from reply to meeting to closed on a simple board.

Campaign analytics

Sends, replies and bounces for every campaign and every mailbox.

Open source

Use Warmbly Cloud and its shared warmup pool, or install it on your own server with one command, where warmup only pairs your own mailboxes.

How it works. Warmbly keeps your mailboxes healthy while you send.

01

Connect your mailboxes

Add Google Workspace, Microsoft 365 or any SMTP and IMAP account. Warmbly checks your domain's SPF and DMARC records and shows the health of every mailbox.

Learn about sending
02

Warm them up

Each mailbox exchanges a small amount of real email with other inboxes, starting at 10 a day and growing slowly. This builds the reputation it needs before your first campaign.

Learn about warmup
03

Send your campaigns

Build a sequence, add your contacts and choose your sending hours. Warmbly spreads the emails across your mailboxes, with a daily limit and a pause between sends for each one.

Learn about campaigns
04

Watch your deliverability

See how much of your mail lands in the inbox at Gmail, Outlook and Yahoo. If a mailbox starts going to spam, Warmbly lowers its volume before it affects the others.

Learn about deliverability

Lead finder. Find the businesses worth emailing.

Draw an area on the map and get every dentist, roofer or bakery inside it, with the people who run them and an address you can trust.

How the lead finder works
app.warmbly.com/app/leads
01

Search any area

Pick a kind of business, go to a city, and search the map or draw the exact area. Only businesses inside it are kept.

02

Find the people

Warmbly reads each business's own website, its team, about and contact pages, for the people who run it, their emails and social profiles.

03

Check every address

Addresses are worked out from each person's name and checked with the business's mail server without sending anything, so you know which are confirmed.

04

Send them a campaign

Add the people or the business to your contacts, a segment and a campaign in one step, with every detail ready as a variable. Or export to CSV or Excel.

Where businesses come from:OpenStreetMapFree, no keyGoogle PlacesYour keyFoursquareYour keyOutscraperYour key
Automations

When this happens, do that.

Every reply, booked meeting, bounce and warmup dip is a trigger. Wire it to your stack on a canvas: branch on intent, post to Slack, open the deal, update the CRM. The one below is running its test right now. Press Test in the window to fire it again.

Explore automations
app.warmbly.com/automations/reply-to-revenue

Branch on anything

Split on reply intent, confidence, where a contact came from or any field the event carries. Yes goes one way, no goes the other.

Act inside Warmbly and out

Open the deal, create a task, label the thread or enrol the contact in a campaign, then tell Slack and update your CRM.

Let AI decide

Ask a yes or no question about the event, or add an AI step that reads the reply and acts, using only the actions you allow.

Test before it runs

A dry run against sample data shows the exact path on the canvas, without sending anything or changing a record.

Works with the tools you already use
  • SlackReply from a channel
  • HubSpotRun your pipeline
  • SalesforceTwo-way sync
  • PipedriveCreate people on reply
  • CloseCreate leads on reply
  • DiscordPing a channel
  • ZapierSend events anywhere
  • MakeStart a scenario
  • n8nTrigger a workflow
  • CalendlyLog booked calls
  • Cal.comLog booked calls
  • MillionVerifierVerify addresses

Pricing. Pay for what you send.

The number on each card is daily send volume. Warmup, the unified inbox and analytics are in every paid plan, and the CRM and the API start on Grow.

Save 20%

Starter

Great for small businesses with a small budget.

$23$29

/ month · billed yearly

Save $72 a year

150 sends a dayup to 4,500 a month
Get started
  • Unlimited warmup
  • Unlimited mailboxes
  • Unified inbox with reply detection
  • Sequences that stop on reply
  • Inbox placement monitoring

Grow

Ideal for growing businesses scaling their outreach.

$71$89

/ month · billed yearly

Save $216 a year

3,000 sends a dayup to 90,000 a month
Get started
  • Everything in Starter
  • CRM with pipelines and deals
  • A/B variants per step
  • Bulk contact import
  • API and signed webhooks

Business

Most popular

For established teams that need higher limits and advanced features.

$263$329

/ month · billed yearly

Save $792 a year

15,000 sends a dayup to 450,000 a month
Get started
  • Everything in Grow
  • Your mailboxes sign in from an address no one else uses
  • Team roles and permissions
  • Full audit log
  • Priority support

Enterprise

Large orgs with custom volume and dedicated support.

Custom

/ month · billed yearly

15,000+ sends a day
Talk to sales
  • Everything in Business
  • Custom volume and contract
  • BYOK encryption · SSO / SAML
  • Custom data residency
  • Dedicated CSM
All plans include warmup, sending, the inbox and analytics.See the full comparison
Warmbly for Agencies

Outreach for clients? One plan covers all of them.

Each client gets its own workspace, and every client sends from one shared monthly pool. No fee per client, no limit on clients, and your brand on the pages clients see.

Agency
$199/ month · billed yearly
150,000 sends a month, shared by every client
  • Unlimited clients, no per-client fee
  • Your logo, colour and portal domain
  • $10 of shared AI each month
Agency Pro
$479/ month · billed yearly
500,000 sends a month, shared by every client
  • Everything in Agency
  • No “Powered by Warmbly” on client pages
  • Sending kept apart from other customers

Sending more than 500,000 a month? Agency Scale sizes the pool to your volume. Talk to sales.

Self-hosting is free and community supported, and it suits teams that want to own the whole stack. A self-hosted instance warms only between its own mailboxes, with no shared pool, so for deliverability Warmbly Cloud is the better choice.

Start sending cold email that lands.

Start a 14-day free trial, no card needed, and warm your first mailboxes today. Unlimited mailboxes and warmup on every paid plan.