AJ Cassata — Founder, Revenue Boost (Instantly Certified)
"Warm Inboxes transformed our cold email deliverability."
Shares how Warm Inboxes helped transform their cold email campaigns and boost client results.
Cold Email Infrastructure — US + EU IPs
The Fastest and Safest Way To
Launch Cold Emails.
Official Google, Microsoft 365 and Azure inboxes. Free prewarmed .com domains. No warmup wait.
Built by operators sending 1M+ cold emails a month.
- Google Workspace inboxes — official, fully managed
- Microsoft 365 & Azure inboxes
- Prewarmed — no warmup wait, sending the day they land
- Every order delivered within 48 to 72 hours of payment
- Free prewarmed .COM/.CO domain with every prewarmed package
- SPF, DKIM, DMARC configured before you log in
- US + EU IP infrastructure
- 24/7 WhatsApp support from real operators
Certifications and partnerships: Clay Verified · Instantly Certified Expert · PlusVibe Technology Partner · Smartlead Partner
Why Cold Emailers Rely On Us
1. Launch with prewarmed inboxes
FREE domains. Fully warmed. Delivered within 48 to 72 hours and sending the day they land. No warmup wait.
2. Ramp volume with fresh infrastructure
Once your campaign is booking meetings, we layer in fresh inboxes on your own branded domains at a fraction of the cost per send. Same deliverability. 3x the output.
3. Keep prewarmed on standby for when infrastructure burns
Cold email is a contact sport. Domains get flagged. IPs get hit. When it happens mid-campaign, the prewarmed inboxes you hold on standby take the volume while the cause is fixed. Pipeline doesn't stall. Meetings keep booking.
What You Get
- Built by operators sending 1M+ cold emails a month — Diversified across US + EU IPs, so one blacklisted range is not the whole fleet. Our controlled placement tests are published separately in the inbox placement log.
- Zero setup headaches — Domains, SPF, DKIM, DMARC, and forwarding handled before you log in.
- 24/7 WhatsApp support from real operators — No tickets. No chatbots. Real humans who run cold email every day.
- Trusted by agencies that can't afford downtime — Agency Velocity, Revenue Boost, PLNitude, Understory, Mailfirst, B2BScale.
Customer Results
- 2,338,200 emails sent · 4.87% reply rate · $6,902,978 in pipeline
- 1,310,300 emails sent · 4.41% reply rate · $3,301,591 in pipeline
- 279,500 emails sent · 4.61% reply rate · $1,025,058 in pipeline
- 790 sequences · 15.44% reply rate · $305,000 in pipeline
Figures as each campaign’s sequencer dashboard reports them, for campaigns run by our agency and by clients. Reply rate is replies divided by emails sent; pipeline is the opportunity value recorded against those replies, not closed revenue.
Integrates With Your Outbound Stack
Works seamlessly with all major cold email tools. No migration. No friction. Plug in and go.
- Instantly.ai
- SmartLead.ai
- EmailBison
- ManyReach
- Clay
- Apollo
- ZoomInfo
- HubSpot
- Cloudflare
- Porkbun
- GoDaddy
Delivery, by product
| Product | Delivered | Warmup | Ready to send |
|---|---|---|---|
| Prewarmed Google Workspace | Within 48 to 72 hours of payment | None, already warmed | On delivery |
| Prewarmed Microsoft 365 | Within 48 to 72 hours of payment | None, already warmed | On delivery |
| Prewarmed Azure tenant | Within 48 to 72 hours of payment | None, already warmed | On delivery |
| Fresh Google Workspace, Microsoft 365 or Azure | Within 48 to 72 hours of payment | 14 to 21 days | After warmup |
An order whose receiving account (the sequencer or registrar we connect to) still has two-factor authentication switched on can take longer.
Pricing
All prices in USD per inbox per month. Prewarmed packages include a free prewarmed .COM/.CO domain and are billed monthly, 2-monthly, or quarterly. Fresh inboxes are billed monthly, quarterly, or yearly.
Prewarmed Inboxes (ready to send on arrival)
| Product | Monthly | 2-Month | Quarterly |
|---|---|---|---|
| Prewarmed Google Inboxes (3 ready-to-use, free domain) | $8/inbox | $7/inbox | $6/inbox |
| Prewarmed Microsoft Inboxes (3 ready-to-use, free domain) | $8/inbox | $7/inbox | $6/inbox |
| Prewarmed Azure Tenant (100 inboxes per tenant) | $0.69/inbox ($69/tenant) | $0.60/inbox ($60/tenant) | $0.50/inbox ($50/tenant) |
Example: 3 prewarmed Google inboxes with a free domain cost $24/month on monthly billing or $18/month on quarterly billing. Lower-cost prewarmed inboxes on non-.COM extensions are available from $4.50/inbox via support.
Fresh Google Workspace Inboxes (your branded domains, 14-21 day warmup)
| Volume | Monthly | Quarterly | Yearly |
|---|---|---|---|
| No minimum | $3.50/inbox/mo | $3.25/inbox/mo | $3.00/inbox/mo |
| 30+ inboxes | $3.25/inbox/mo | $3.00/inbox/mo | $2.50/inbox/mo |
| 100+ inboxes | $3.00/inbox/mo | $2.50/inbox/mo | $2.00/inbox/mo |
Fresh Microsoft 365 and Azure
| Product | Monthly | Quarterly | Yearly |
|---|---|---|---|
| Microsoft 365 | $3.00/inbox/mo | $2.50/inbox/mo | $2.00/inbox/mo |
| Microsoft Azure Tenant (25-100 inboxes) | $50/domain/month | - | - |
Warm Rotation = Maximum Deliverability
A mailbox that sends hard every week burns down. Rotation gives every set a week of rest before it is ever pushed again, so the volume keeps moving and the reputation never does.
Advanced deliverability monitoring at the domain, inbox and sequencer level
Monitor your infrastructure’s deliverability no matter where you bought it from: every monitored domain checked daily against eight blacklists, plus SPF, DKIM, DMARC and expiry, with placement per mailbox and reply and bounce rates per sequence in the dashboard now in closed beta.
Closed beta. The blacklist checks run today as a managed service across eight lists; the monitor dashboard is being built on top of them, which is why the app marks it coming soon. We onboard in waves.
Automated Reconnections
Every time Google asks for a phone number to check a human owns the account, or an OAuth token fails and has to be reissued, our technicians reconnect the mailbox. Nothing to raise and nothing to reconnect yourself.
Client Workspaces
File each client’s orders and domains in its own workspace, with its own sequencer login and its own reconnection and deliverability monitors, so one agency account runs every client without mixing them up.
What Our Customers Say
Leevi — Founder, Agency Velocity (Instantly Certified)
"Easiest way to launch cold email."
Shares how Warm Inboxes provides the easiest way to launch cold email campaigns.
Naufal — Head GTM Engineer, Understory (Clay Certified)
"Warm Inboxes delivers exceptional results."
Shares how Warm Inboxes helped optimize their go-to-market email strategy.
Papa — Founder, Leveraged Outbound
"Our infra was completely burned and Warm Inboxes saved us from losing clients."
When infrastructure was completely burned, Warm Inboxes got new prewarmed inboxes deployed fast and kept the pipeline alive.
Emmanuel — Founder, PLNitude (Smartlead Certified)
"Getting new clients through our cold email infrastructure."
Upscale's cold email infrastructure helped him acquire new clients consistently.
Frequently Asked Questions
What is Warm Inboxes?
Warm Inboxes is your trusted platform for purchasing prewarmed and regular email accounts for Google Workspace and Microsoft 365. We ensure your accounts are ready for successful email outreach, with a focus on high deliverability and ease of setup.
Why Choose Warm Inboxes?
We make it simple to get started with prewarmed email accounts that are optimized for deliverability. Our accounts use both US and EU IP addresses and are carefully configured for cold outreach success. Whether you need prewarmed or normal mailboxes, we've got you covered.
How Does Warm Inboxes Improve Email Deliverability?
Prewarmed email accounts start with established sending history, so there is no warmup wait before you send. We handle the technical essentials, including proper configuration of DKIM, SPF, and DMARC records, saving you time and effort.
Which Email Providers Do You Support?
We provide email accounts on Google Workspace and Microsoft 365/Azure.
Do I Have Full Access to My Mailboxes?
Yes, you'll have complete control of your email accounts, including admin access, so you can manage them with ease.
Can I Use My Own Domains with Warm Inboxes?
Absolutely. If you already own a domain, we can help you set it up with mailboxes and ensure everything is configured correctly for optimal performance.
Do You Offer Prewarmed Email Accounts?
Yes, we specialize in prewarmed email accounts. They arrive with their sending history already built, so you can start sending as soon as they are delivered.
Can I Purchase Domains Through Warm Inboxes?
Yes, you can purchase .com domains for only $12 USD. A domain you pay for through us is yours, and can be transferred to you on request. Free prewarmed domains are included with every prewarmed inbox package.
How Does Your Pricing Work?
Prewarmed inboxes are $8/inbox/month on monthly billing, $7 on 2-month, and $6 on quarterly, sold in ready-to-use packs of 3 with a free prewarmed .COM/.CO domain, so a 3-inbox package is $24/month (or $18/month on quarterly). Prewarmed Azure tenants are $0.69/inbox/month with 100 inboxes per tenant. Fresh Google Workspace inboxes run $3.00 to $3.50/inbox/month and fresh Microsoft 365 inboxes $2.00 to $3.00/inbox/month depending on volume and billing cycle. Sales are final once a licence is activated or setup has begun; the refund policy below has the one exception.
What's Your Refund Policy?
Sales are final once a licence has been activated or setup has begun. The one exception is an unused licence: a refund may be considered under the Refunds section of our Terms if the licence was never activated or accessed, no setup or resources were allocated, and you ask within seven days of purchase. Review the Refunds section of our Terms or reach out with any questions before making a purchase.
Free Email Deliverability Tools
- Blacklist Checker — Check domain/IP against 20+ email blacklists
- Deliverability Checker — Grade SPF, DKIM, DMARC, MX, blacklist status and domain age, A to F
- DMARC Checker — Validate your DMARC record and policy
- SPF Checker & Generator — Look up or build a valid SPF record
- DNS Checker — Query MX, TXT, CNAME, A and all DNS record types
- Domain Expiry Checker — Monitor domain expiration dates