First 100 Inboxes Free
Official Outlook Inboxes
100% Automatic Creation
SPF/DKIM/DMARC Configuration
Designed For Cold Email
First 100 Inboxes Free
Official Outlook Inboxes
100% Automatic Creation
SPF/DKIM/DMARC Configuration
Designed For Cold Email
| Features | Microsoft | |
|---|---|---|
| Price Per Inbox | $0.06/month (More Affordable) |
$8/month (Expensive) |
| Inboxes Per Domain | 100 Inboxes | 3 Inboxes Only |
| Cost of 100 Inboxes | Just $16 ($10 X 1 domain + $0.06 x 100 inboxes) |
$1,150 ($10 X 35 domains + $8 X 100 Inboxes) |
| Warm-Up Period | 3 Days | 14-28 Days |
| Enterprise Usage | Used By 71% of Fortune 500 | Not Used By Enterprises |
| Outreach Restrictions | Less Strict (Fewer Headaches) |
More Strict (More Limitations) |
| Best For | High Volume Outreach | Low Volume Outreach |
| Deliverability | Better for High Volume | Better for Low Volume |
| Domain Burning Risk | Significantly Lower | Domains Burn Frequently |
| Feature | Unlimited Inboxes | Other Resellers |
|---|---|---|
| Price (100 Inboxes) | $6 Only 0 Markup |
$50 - $400 10X - 80X Markup |
| Cost for 1M Emails | $501 / Month | $6,700 / Month |
| Delivery Time | 10 - 20 Minutes | 2 - 3 Days |
| Infrastructure Owner | You | The Reseller |
| What You Pay For | The Technology | Ignorance |
| Scale to 10k+ Inboxes | Instant (1 Click) | Manual Order & Wait |
| If Inbox Burns | Instant Replace (Free) | Buy New (Full Price) |
| Management Dashboard | Advanced Panel | Spreadsheet / None |
| Sending & Warmup Settings | Fully Configured | No |
| Real Outlook Inboxes | Yes | Yes |
| Dedicated IP | Yes | Yes |
| Deliverability | High | High |
| Email Software Integration | Yes | Yes |
| 100% Automated Setup | Yes | Yes |
| DNS Authentication | Full | Full |
| 24x7 WhatsApp Support | Yes | No |
Either buy a high-quality US IP tenant directly from us (instant), or connect your existing Microsoft tenant in one click. Result: 100% Verified Infrastructure Ready.
Sign in to your dashboard. Enter the domain you want to use and set a master password for your mailboxes. This is the only manual work you do.
While you grab a coffee, our system automatically handles the complex DNS technicalities and plumbing.
Download your pre-verified CSV file. Upload it directly to Smartlead, Instantly, or any sending tool. Start launching campaigns immediately.
Unlimited Inboxes is a platform that is designed to automate the creation of Microsoft inboxes on scale so that you can use them to send cold emails
Using Unlimited Inboxes, you can create Microsoft Outlook inboxes with a professional domain which is the best type of infrastructure for high volume cold outreach
Yes. They are 100% real.
We will provide you emails and passwords which can be used to log in as well directly to Microsoft too.
If you plan on doing high volume automated cold email, Microsoft is outperforming every other alternative right now if the thing you care about is the overall ROI
You can use either Microsoft or Google Or Custom SMTP providers for sending emails right now
SMTP is too complicated to get right for 99.99% people reading this so forget it
Google is great but has some issues compared to Microsoft which I covered in a section on this website separately
Some reasons why Microsoft outperforms Google:
1. Cost ($6 for 100 inboxes vs $800 for inboxes if you use Google)
2. Warmup time (Microsoft needs 3 days, Google needs 14 - 28 days)
3. Leniency (Google is super strict but Microsoft is lenient with you sending outreach messages, which means you have more room for errors without being punished)
4. Inboxes per domain (100 on Microsoft vs 3-4 on Google)
5. Domain burning risk (low on Microsoft and high on Google)
In short, Google is great for sending super low volume personalised emails
Microsoft is great for blasting high volume cold emails because its:
- Affordable
- Less punishing
- Better for deliverability at scale
It's not even a comparison
You cannot compare an fighter jet production plant with a fighter jet
Other resellers provide you a fighter jet that works and charge you a massive markup because you're not smart enough to build them yourself
We provide you a factory with everything ready to produce fighter jets
You just turn it on, pay the rent for the same and build aircrafts at scale affordably without any markups
Resellers profit from your ignorance and lack of knowledge
We destroy their ability to do so by providing you the technology used by them to create inboxes
If that wasn't convincing enough, here are some other reasons:
1. Price per 100 inboxes ($6 if you choose us vs $50 - $400 with resellers)
2. Delivery time (10 - 20 minutes with us vs 2-3 days with resellers)
3. Owner of infrastructure (you if you choose us, the reseller if you don't)
There's not a big difference in quality of the inboxes unless you choose a really bad reseller, the main difference is in the cost because you're not paying markups for ignorance and the ease of scaling with us vs them.
We don't charge any markups on inboxes
You just pay a flat monthly fee to access the technology for inbox creation
We were resellers too at some point exploiting people's inability to create 100 inboxes for $6 but then everyone in the industry started competing on price which is never a smart idea in business
We decided to f*ck up all resellers by giving what they give with 0 markups
Our profit margins on Unlimited Inboxes is 99.9%+ so we can keep prices low and capture the entire share of the market
We are not competing with resellers, we made something completely different and we make money in a different way
You need 3 things:
1. Technology (our platform) to automate the process of creation and configuration of the inboxes
2. Domain (to connect to inboxes to get better deliverability and results)
3. Microsoft Tenant (which you can buy from Microsoft for $6/mo or from us if you want USA high quality IPs)
We've made a full free course on how to get started so don't worry, you won't run into any problems
You can connect one inbox per tenant
You can create 100 inboxes on one tenant
After analysing millions of emails sent, the best sending settings for Microsoft is:
- 5 cold emails per inbox daily
- 5-7 warmup emails per inbox daily
So for $6 (cost of one tenant) you can send around 5x100 = 500 cold emails daily = 15000 cold emails monthly
By default we use Girl names when creating inboxes cause that has the highest reply rate but you're free to choose any name you prefer before creating inboxes
Whenever you want to create inboxes, you need something called a tenant from Microsoft (think of it like a license for creating inboxes)
One tenant costs $6 which you pay directly to Microsoft, not us. We make 0 profit on it.
The only place we make profit is when you use our platform to create the inboxes for which we charge a flat monthly fee
You pay the monthly fee to access the technology, nothing extra to us
$6 you pay for each 100 inboxes you create to Microsoft
This is still always gonna be more affordable than buying from resellers
For example, if you wanna send 1M emails a month, the cost of the same will be:
- $501/mo with us
- $6700/mo with resellers
No
We add all the DNS records for you
No need to do anything
Yes
You can buy any domain you want and connect it to create inboxes
The type of domain doesn't really matter
If budget is not an issue, buy a .com domain
If you wanna keep costs low, use a .info domain
Buy the domain from any reputed site like Namecheap, Hostinger, Porkbun, Spaceship etc.
It doesn't really matter that much.
Microsoft warm up is significantly faster than Google and 99% people face 0 issues with a 3-5 day warm up period.
Google takes 14-28 days for reference.
This means you can start your campaigns faster and make money faster.
5 warmup emails daily
Increase the number of warmup emails sent by 1 daily (OPTIONAL)
Do this till you send 7 warmup emails (OPTIONAL)
Set reply rate to 35% - 40%
Yes, no one except you can use them.
They are 100% private as we literally create them on your domain (not giving you some crappy ones)
Yes. If any email infrastructure provider says no he is lying to you.
If I use any service and send phishing links to a random list, the domain will get burnt.
Microsoft is more lenient than Google so the chances of burning is significantly lower but it is still there.
It depends mostly on what you are sending in your emails and the quality of your list.
Just buy a new domain it is cheap.
You can change the domain on a Microsoft Tenant easily so no extra cost for replacement.
Yes, you can add it to any email sending tool like Instantly, Smartlead, Manyreach, PlusVibe (Pipl AI), Email Bison etc.
Many of them support bulk uploads too so no manual work needed.
No.
We provide real Outlook accounts which you can connect via oAuth which means 0 disconnects.
Your IP depends on where you're sourcing your Microsoft Tenants from
If you source free Tenants by opting in for free trials or try to get cheap business licenses by using tricks like Indian/Vietnamese IP, you're gonna get a low quality IP
Either you become a Microsoft Cloud Service provider (partner) so that you can provision tenants at cost but it takes time, involves paperwork and is not worth it for most people in my opinion
If you buy Tenants from https://unlimitedinboxes.com/tenant, you will get a dedicated US IP for each tenant which means your infrastructure doesn't use a shared IP which leads to better deliverability
Most resellers make their money from selling inboxes.
I make most of my money from cold outreach.
I work with 50+ B2B companies as of Oct 2025 and do outbound on their behalf.
They literally trust us with their survival cause we know what we are doing.
We have worked with companies of all sizes (including those with 10000+ employees who get shipping contracts from the US Navy).
I do this daily, have tried every method of outbound and know what works.
Probably the only person in the industry who does this.
In the B2B industry, the average ROI with cold email is 36X.
Yes, on AVERAGE a company that invests $1 gets $36 out.
The average cold emailer doesn't know what they're doing and is using the wrong system etc..
You are using infrastructure better than the average cold emailer, does that not imply your results will be better than the average cold emailer?
That means you will get an ROI greater than 36 times hypothetically.
Numbers don't lie, I have created an ROI calculator.
Go and plug in your business numbers and see how much you make and save if you choose us :)
Click on the Chat Widget at the bottom right corner of the screen. We will get back to you there.
Just look at the video demo of the platform to see how easy it is to use it
If you can copy paste text on a screen and type, you will be able to figure it out