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.
Open sourceSelf-host the whole platform · Apache 2.0Apache 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.
Free plan with 10 mailboxes · No credit card · Free to self-host
Everything you need to run cold email.
Connect your mailboxes, warm them up, send campaigns and handle the replies, all from one dashboard.
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, or install it on your own server with one command.
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
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 automationsapp.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, analytics, CRM and the API are in every paid plan.
Save 20%
Starter
Great for small businesses with a small budget.
$23$29
/ month · billed yearly
Save $72 a year
150 sends a day
Start free
- 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 day
Start free
- Everything in Starter
- CRM with pipelines and deals
- A/B variants per step
- Bulk contact import
- API and signed webhooks
Business
Most popularFor established teams that need higher limits and advanced features.
$263$329
/ month · billed yearly
Save $792 a year
15,000 sends a day
Start free
- 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, inbox, analytics and CRM.See the full comparison
Self-hosting is free. When Warmbly Cloud launches, link your instance and we warm up to 10 of your mailboxes in the shared pool at no cost, unlimited for $15 a month.
Start sending cold email that lands.
Connect a mailbox and start warming it today. Free to start, free to self-host.