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Reputable domains and mailboxes for cold email, from $0.49. Register domains, create mailboxes, set SPF, DKIM and DMARC, and push everything to Instantly or Smartlead — from the dashboard, from code, or with one message to Claude, Cursor or n8n over MCP. 95%+ deliverability either way.
Mailboxes built for outbound.
Run by your AI agent.
10M+
emails sent per day
400k+
mailboxes managed
4.7
G2 rating with 197 reviews
Run your whole sending setup from your AI assistant
Maildoso ships a hosted MCP server. Connect it to Claude, Cursor, n8n or any MCP client with your token, and your agent registers domains, creates mailboxes, exports them to your sequencer and checks what's blocked — from a plain-language request. Everything in your sending infrastructure is an API call, so everything is something an agent can do for you.
Provision
Register 6 domains and create 30 mailboxes for the Q3 campaign. Domains bought, SPF/DKIM/DMARC set, mailboxes ready to send.
Connect
Export all new mailboxes to Smartlead." No CSV, no import screen. The agent pushes them straight into Instantly, Smartlead or your tool of choice.
Monitor and repair
Which domains are blocked right now? Replace them. The agent pulls your stats, flags what's down and provisions replacements.
Trusted by 7,000+ Companies!
Achieve 95% Deliverability
We provide reputable mailboxes and domains built specifically for outreach and optimized for deliverability — so your emails actually land in the inbox.
Set Up Domains and Mailboxes in Under 10 Minutes
Step 1
Register domains directly in our dashboard (or connect your own ones)
Register domains directly in our dashboard (or connect your own ones)
Step 2
Enter mailbox names – SPF, DKIM, and DMARC are auto-configured
Enter mailbox names – SPF, DKIM, and DMARC are auto-configured
Step 3
In 10 minutes, your mailboxes are ready to export and use with any outreach platform
In 10 minutes, your mailboxes are ready to export and use with any outreach platform
Step 4
Set up integration with popular platforms – Instantly, Smartlead, Saleshandy, and others
Set up integration with popular platforms – Instantly, Smartlead, Saleshandy, and others
Already Have Domains? Connect Them to Maildoso!
Add them to your dashboard or reach out to our support team for assistance (and if you don’t have any domains yet, you can register them with us in just 5 minutes).
You can set up domain redirects in just a few clicks and always know whether a domain is active or blocked, plus how many mailboxes are linked to it.
Why B2B Teams Choose Maildoso for Cold Email Setup
Connect your mailboxes in one click!
No more downloading or importing. With the click of a button, your mailboxes automatically sync with Instantly, Smartlead or EmailBizon.
Your primary domain is safe!
We keep it securely protected behind CAPTCHA — bots and scanners won’t be able to link it to your secondary domains.
Deliverability consulting
Having trouble with deliverability?
We’ll review your campaigns, run deliverability tests, and check your copy.
We’ll review your campaigns, run deliverability tests, and check your copy.
Stop wasting hours on manual domain registration and technical configurations. Maildoso provides a complete outbound email infrastructure that scales with your agency or sales team.
Use Our Free Resources!
Refer new users and earn a 20% reward
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Best practices for improving deliverability in a single article.
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All the answers about the warm-up filter and master inbox.
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A community of 1,400+ professional cold emailers.
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Step-by-step algorithm for launching your first campaign.
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Check out the recordings of webinars or sign up for the next one!
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Experts who can help you with outbound
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Expert pool
Simple rules to make your copy more native
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Learn more about new features and products
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Maildoso is game changer for deliverability. Use it personally!
Dhruv Patel, co-founder of Saleshandy
What our customers say
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FAQ
Find more answers in our Knowledge Base or ask our support team
Maildoso uses monthly pay-per-mailbox pricing.
As of June 2026 the plans are:
Every plan includes self-healing mailboxes, IP rotation, CAPTCHA domain protection, API and MCP access, free deliverability audits, and a 30-day money-back guarantee.
As of June 2026 the plans are:
- 30 mailboxes for $75/month ($2.5 per mailbox),
- 300 mailboxes for $225/month ($0.75 per mailbox),
- and 1,000 mailboxes for $499/month ($0.49 per mailbox).
Every plan includes self-healing mailboxes, IP rotation, CAPTCHA domain protection, API and MCP access, free deliverability audits, and a 30-day money-back guarantee.
We offer SMTP mailboxes designed specifically for outbound campaigns.
Advantages of SMTP:
Can I delete mailboxes?
Yes.
You purchase a license for a specific number of mailboxes rather than specific accounts. If you delete and recreate them, you don't need to pay extra. However, please note that new mailboxes require a warm-up period.
How do I change the names of mailboxes?
Find out in our Knowledge Base.
Advantages of SMTP:
- Designed specifically for outbound
- Lower cost (starting from $0.49)
- Fully proprietary infrastructure, including servers and IPs
- Your campaigns are sent from different IPs, and we automatically replace them with new ones if they stop working
- We automatically replace links and images in your emails with safe alternatives using Global Customer Domain Tracking
- Burned-out mailboxes are automatically disconnected from campaigns for 14 days to recover
- We run inbox placement tests every 3 days and display up-to-date health scores for each mailbox.
Can I delete mailboxes?
Yes.
You purchase a license for a specific number of mailboxes rather than specific accounts. If you delete and recreate them, you don't need to pay extra. However, please note that new mailboxes require a warm-up period.
How do I change the names of mailboxes?
Find out in our Knowledge Base.
Are domains included in the plans?
Yes, but only for quarterly SMTP plans. For monthly plans, they must be purchased separately, or you can connect your existing domains.
How much do domains cost?
The domain registration fee is $12 per year. This price is fixed and does not change based on the number of domains.
Please note: Starting October 1, 2026, domain registration will be $15/year.
You can purchase domains on the pricing page or in your personal account on the Packages & Add-ons page.
Which TLD's are available for domain registration?
We use the following TLDs for domain registration: .com, .net, .org, .one, .co, .email, .ink, .digital, .company, .pro, .services, .space, .co.uk, .de.
Can I connect my own domains? Yes. To do this, send a list of your domains to our support team via the website chat or at [email protected]
You can also connect external domains yourself via the API. For this, consult the API documentation and watch our Loom video.
Do I retain ownership of domains purchased through Maildoso?
While you are using our service, domains are registered with us, enabling us to facilitate processes such as creating emails, IP rotation, and more.
You can request that the domains be returned at any time, and we will transfer them back to you at no charge at the end of your subscription.
How many mailboxes can I create per domain?
Up to 99 mailboxes per domain, but we recommend no more than 8.
Yes, but only for quarterly SMTP plans. For monthly plans, they must be purchased separately, or you can connect your existing domains.
How much do domains cost?
The domain registration fee is $12 per year. This price is fixed and does not change based on the number of domains.
Please note: Starting October 1, 2026, domain registration will be $15/year.
You can purchase domains on the pricing page or in your personal account on the Packages & Add-ons page.
Which TLD's are available for domain registration?
We use the following TLDs for domain registration: .com, .net, .org, .one, .co, .email, .ink, .digital, .company, .pro, .services, .space, .co.uk, .de.
Can I connect my own domains? Yes. To do this, send a list of your domains to our support team via the website chat or at [email protected]
You can also connect external domains yourself via the API. For this, consult the API documentation and watch our Loom video.
Do I retain ownership of domains purchased through Maildoso?
While you are using our service, domains are registered with us, enabling us to facilitate processes such as creating emails, IP rotation, and more.
You can request that the domains be returned at any time, and we will transfer them back to you at no charge at the end of your subscription.
How many mailboxes can I create per domain?
Up to 99 mailboxes per domain, but we recommend no more than 8.
How many emails can I send from one mailbox?
You can send up to 15 cold emails / 80 warm-up emails per day, no slow ramp-up (clarify if your sequencer allows for this volume of warm-up emails).
Can I send emails to free email hosting services (@gmail.com, @yahoo.com, etc.)?
Our infrastructure is optimized for B2B outreach. As a result, campaigns targeting personal email providers may experience reduced inbox placement.
You can send up to 15 cold emails / 80 warm-up emails per day, no slow ramp-up (clarify if your sequencer allows for this volume of warm-up emails).
Can I send emails to free email hosting services (@gmail.com, @yahoo.com, etc.)?
Our infrastructure is optimized for B2B outreach. As a result, campaigns targeting personal email providers may experience reduced inbox placement.
All current prices are available on the pricing page.
Do you offer discounts?
No, we have a no-discount policy. Our prices are the same for all users, and we do not run promotions or sales.
Instead, we offer affordable pricing from the start, without the need for discounts. For instance, we offer the lowest prices on the market for SMTP accounts (starting at $0.49).
What if I need a specific number of mailboxes?
You can set up a custom plan on the Packages & Add-ons page and choose the exact number of mailboxes and domains you need.
I need more than 10,000 mailboxes.
Special conditions apply for high volumes. Contact our AE team via the website widget or by filling out this booking form.
Do you offer discounts?
No, we have a no-discount policy. Our prices are the same for all users, and we do not run promotions or sales.
Instead, we offer affordable pricing from the start, without the need for discounts. For instance, we offer the lowest prices on the market for SMTP accounts (starting at $0.49).
What if I need a specific number of mailboxes?
You can set up a custom plan on the Packages & Add-ons page and choose the exact number of mailboxes and domains you need.
I need more than 10,000 mailboxes.
Special conditions apply for high volumes. Contact our AE team via the website widget or by filling out this booking form.
Yes. Maildoso's API and MCP server let you register domains, create mailboxes, and set up SPF, DKIM and DMARC programmatically, then export them straight to your sequencer. You can even run the whole setup from an AI assistant like Claude. It's the fastest way to scale your sending infrastructure alongside a growing lead list.
Thank you for choosing us! Here are your next steps:
1) Authorization
For some of our plans, you need to authorize first — in this case, you can log in immediately, and your mailbox license will already be available.
If you didn't authorize during checkout, your login credentials will be sent to the email address used in Stripe. Check your spam folder if you don't see them.
2) Connecting Domains
If you have your own domains, send the list via chat or to [email protected]; they will be connected within 24 hours. If you don't have domains, you can buy them for $12/year on our pricing page or on the Packages & Add-ons page.
3) Registering Mailboxes
Go to the 'Accounts' page and click 'Add more email accounts'.
Enter the first and last names, and select the domain. You can auto-fill multiple lines at once.
Need more than 4? Click 'Add new line'.
4) Connecting to your Sequencer
Select the accounts, click 'Export selected to CSV', and choose your format (we support 9 sequencers natively).
More info here.
How long does it take?
5) Warm-up
For any new mailboxes and domains, you must run a warm-up for at least 14 days before launching your first campaign. Keep warm-up active for the entire lifespan of the mailboxes, using the maximum volume possible — you can combine different providers or use the Instantly.ai warm-up pool.
Warning: Skipping warm-up prevents your mailboxes from building domain reputation and almost always results in them burning out.
1) Authorization
For some of our plans, you need to authorize first — in this case, you can log in immediately, and your mailbox license will already be available.
If you didn't authorize during checkout, your login credentials will be sent to the email address used in Stripe. Check your spam folder if you don't see them.
2) Connecting Domains
If you have your own domains, send the list via chat or to [email protected]; they will be connected within 24 hours. If you don't have domains, you can buy them for $12/year on our pricing page or on the Packages & Add-ons page.
3) Registering Mailboxes
Go to the 'Accounts' page and click 'Add more email accounts'.
Enter the first and last names, and select the domain. You can auto-fill multiple lines at once.
Need more than 4? Click 'Add new line'.
4) Connecting to your Sequencer
Select the accounts, click 'Export selected to CSV', and choose your format (we support 9 sequencers natively).
More info here.
How long does it take?
- Registering a new domain: up to 15 minutes.
- Adding an existing domain: up to 24 hours.
- Registering a mailbox: 5 minutes.
5) Warm-up
For any new mailboxes and domains, you must run a warm-up for at least 14 days before launching your first campaign. Keep warm-up active for the entire lifespan of the mailboxes, using the maximum volume possible — you can combine different providers or use the Instantly.ai warm-up pool.
Warning: Skipping warm-up prevents your mailboxes from building domain reputation and almost always results in them burning out.
The easiest way is to use our website chat widget.
Support hours: US (ET): 2 AM – 5 PM / Europe (CET): 8 AM – 9 PM
Average response time during working hours is 20 minutes.
You can also email us at [email protected] or join our Slack Community.
My emails aren't reaching recipients. What should I do?
First, consult our Deliverability Guide – it solves most issues.
Additionally, all clients can request an audit from Maildoso experts: we will run tests and check your copy for spintax and spam words. You can book your session by clicking the "Deliverability Audit" button in your dashboard.
You can also reach out to our community experts — they can assist you with campaign setup, lead mining, consulting, and training. Please note that since these experts are not part of Maildoso, we cannot be held responsible for the quality or cost of their services.
Support hours: US (ET): 2 AM – 5 PM / Europe (CET): 8 AM – 9 PM
Average response time during working hours is 20 minutes.
You can also email us at [email protected] or join our Slack Community.
My emails aren't reaching recipients. What should I do?
First, consult our Deliverability Guide – it solves most issues.
Additionally, all clients can request an audit from Maildoso experts: we will run tests and check your copy for spintax and spam words. You can book your session by clicking the "Deliverability Audit" button in your dashboard.
You can also reach out to our community experts — they can assist you with campaign setup, lead mining, consulting, and training. Please note that since these experts are not part of Maildoso, we cannot be held responsible for the quality or cost of their services.
To cancel your subscription, please contact our support team via the chat widget on our website or by email at [email protected].
Please note: We offer a 30-day money-back guarantee for all new users (available for monthly SMTP packages).
In all other cases, please refer to our Refund Policy.
Please note: We offer a 30-day money-back guarantee for all new users (available for monthly SMTP packages).
In all other cases, please refer to our Refund Policy.
If you use our mailboxes and are happy with the results, we would appreciate it if you could leave a review on Maildoso G2 page.
We also have an affiliate program — tell your friends and colleagues about us and receive 20% of their payments. You can sign up on the Tolt registration page.
If you would like to become our ambassador, please contact Vlad, our Head of Marketing ([email protected], LinkedIn page).
We are also always looking for webinar speakers!
If you have insights to share with our audience (5,000+ product users, 15,000+ LinkedIn followers, and 1,400+ Slack Community members), write to Vlad, and he will organize everything (you can watch our previous webinars on the Maildoso Webinar page).
We also have an affiliate program — tell your friends and colleagues about us and receive 20% of their payments. You can sign up on the Tolt registration page.
If you would like to become our ambassador, please contact Vlad, our Head of Marketing ([email protected], LinkedIn page).
We are also always looking for webinar speakers!
If you have insights to share with our audience (5,000+ product users, 15,000+ LinkedIn followers, and 1,400+ Slack Community members), write to Vlad, and he will organize everything (you can watch our previous webinars on the Maildoso Webinar page).