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How to Build your own SMTP email server and send unlimited emails?

How to build SMTP server for cold emailing

In this post, we are going to see how to setup SMTP server for cold emailing with minimum investment or for free if you are eligible. Cold Emailing can be your gateway to success for a digital marketing business. But commercial bulk email senders like Sendinblue, Mailchimp, sandblaster, and send grid often limit the number of emails that can be sent per day and for free accounts that is mostly limited to 50-300 emails per day. If your setup your own SMTP server, you can virtually send unlimited emails with your custom domain without having to pay excessive fees to email service providers.

What is an SMTP Server?

An SMTP (simple mail transfer protocol) server is a server that lets you send emails from your own domain name and does the email routing for you. It enables you to send emails over the internet and ensure their routing to the destination.

To understand fully how SMTP server works we need to understand how actually email works.

How Emails Actually work?

Email works just like our traditional postal services and SMTP acts as a postman on the internet. When you send an email, it may seem like a message is sent instantly. The reality is that a complex series of transfers take place between different email servers running SMTP protocol. Without this series of mail servers, you would only be able to send emails to people whose email address domains matched your own – i.e., you could only send messages from one account to another account.

how email works

Why do we need a personal SMTP server?

Sending cold emails require a lot of emails to be sent at once or at regular interval. Major email service providers limit the number of emails sent per day or they charge you extra for sending more number of emails. So, if you have your own SMTP server, you can virtually send unlimited emails and you are in total control. The email limit of some of the major bulk email providers is given below:-

Number of free emails allowed by bulk email providers

Email Service ProviderNumber of Emails Allowed per day
Elastic Mail100
Mailer Lite12,000/ month
Mailer Jet200
Mail Chimp2000
Send grid100
Amazon SESFirst 62,000 emails free

Basic Requirements to Setup SMTP server for unlimited emails

In order to build an SMTP server and send emails with your custom domain, you actually need three things.

  • A VPS provider like Digital Ocean, Amazon AWS, Azure or Vulture.
  • A custom domain name.
  • A bulk Email Software.

How to get VPS for the SMTP server?

An SMTP server can be setup on a local machine but the best way to setup an SMTP server is to hire a VPS server in the cloud that will provide you 24x hrs availability and easy configurations. Now major cloud providers like Google, AWS, Digital Ocean and Vulture provide 5$-6$ per month VPS machines that are enough for our SMTP server.

What is a VPS server?

A VPS( virtual private server) is just a computer that is running in the cloud that can be used to host your application, or website or perform computationally expensive tasks. Different cloud providers name their VPS servers in different ways. For example, the digital ocean calls them droplets and AWS calls them EC2 instances.

Free VPS for SMTP server

You can get trials for major cloud providers ranging from one to three months and see if you are satisfied with their service. To get digital ocean 100$ free credit for three months visit the following link.

DigitalOcean Referral Badge

If you are a student, you can get the limit of digital ocean free credit extended for complete one year by claiming GitHub student package. Github student package included many other free services as well like Canva pro for 12 months etc.

How to get Domain Name for SMTP server?

A domain name is a customized name that you send emails from. For example [email protected]. However, it is recommended that for cold emailing, you buy a separate domain name like If your domain name gets blacklisted due to massive amount of emails, your business domain is not impacted then.

A domain name ending in dot com or dot net can be purchased for approximately 10$ per year. Domain can be bought from any domain provider like name, GoDaddy or NameCheap. Just go to your domain name provider and buy a domain name for your SMTP server.

How to get a free domain name for cold emailing?

If you are a student, then you can get free domain names from the Github student pack. To learn how to get a free GitHub student pack, you can check our tutorial for getting canva pro for free. With the Github student pack you can get the following domain names for free for a year.

  • .me domain name from Namecheap
  • .tech domain name for dot tech
  • .rocks etc from
Get a .COM for just $5.98!

If you want a free domain for life, you can go to and here you can get free domains ending in the following extensions:-

  • .tk domain name
  • .ml domain name
  • .cf domain name
  • .gq domain name

How to Setup Free SMTP Server?

Now, once we have both the domain names and the VPS service subscription. We can now proceed to setup our free SMTP server. For the tutorial, I am using the digital ocean cloud provider and Namecheap as the domain registrar.

1. Create a droplet on the Digital ocean for SMTP server.

First of all login into your digital ocean account and then click create Droplets.

create droplet in digital ocean

now go to the marketplace and select the option to “see all marketplace apps

digital ocean marketplace apps

Now search for CyberPanel in the marketplace. Now, choose the CPU option, a basic CPU with cost of 5$/month will suffice for our SMTP server.

cyberpanel on digital ocean

For authentication, you can use a password and enter your password for the VPS server. Now click create. It will take 1-2 minutes to process the creation of your VPS server.

VPS server login on digital ocean

After the creation of your VPS machine, your server will appear under the resources tab.

setup VPS on digital ocean

2. Setup Cyberpanel SMTP server for cold emailing

Now, we have setup the cyberPanel on our VPS server. Next step is to setup SMTP server on cyberPanel. Now run a power shell on your PC. Copy the IP address of the machine from digital ocean resources tab and SSH into the cyberPanel with following command. You can also use putty for SSH into cyber panel VPS.

ssh [email protected]
ssh cyberpanel

Give it the password you created when creating VPS on digital ocean. it will ask for an update. Go and update it.

update cyber panel on digital ocean

Now to change the admin password of the cyberPanel, you can use the following command.

adminPass ammaR@1234debian
change password on cyber panel

The window will now show you the IP address that you can use now to access your cyber panel dashboard. Copy the link ending with port number “8090” and paste it into chrome to open the dashboard.

cyber panel ip for accessing

Cyber Panel dashboard will ask for the password. Login with the credentials you just created.

cyber panel dashboard

Now, once the panel is created. You need to create a website. Click on websites and then Create Website.

free SMTP server

Fill in the details with your domain name. Ensure that options for SSL, DKIM and open_basedir are selected.

create a free SMTP server

Now, we need to add DNS records for our VPS server to or nameserver. To get the required records. Go to DNS section and select Add/delete records.

cyber panel DNS settings

How to add DNS records for SMTP server?

You need to add A, txt , mx and cname records for the cyber panel. Get these records from the record section on Cyber Panel.

DNS setting cyber panel
DNS records for SMTP server

Now go to NameCheap , Go to manage DNS and add these records. These records will ensure that your emails are routed properly and do not end up in spam.

Build free SMTP server

Now go back to the cyber panel and add SSL encryption for email. Go to SSL, select email and then click issue SSL.

ssl for SMTP server
SSL email

Create an email address for cold emailing on a personal SMTP server

You can now create an email address. Go to email section and click create email.

email for cold emailing

Now enter the name of account you want to create and the password for it.

free email address for cold emailing

You can now use web email to check if the email address is successfully created or not. You can use the same interface to check incoming emails.

web email cyberpanel

Login with your credentials.

webmail SMTP

You can try sending email to see if lands in your inbox.

setup SMTP server
inbox smtp email

3. SMTP credentials for SMTP server

To see the credentials for your SMTP server. Go to the email section and select List emails.

SMTP credentials for SMTP server

Now, scroll down to the bottom. You have to note down the SMTP credentials that will be used in the email client.

Free SMTP server for cold emailing

Setup free bulk Email software with SMTP server

Once we have setup Cyber panel and have credentials for our SMTP server. Next step is to download and setup bulk email software. There are various commercial bul email software available like Send Blaster but for the tutorial, we are going to use H-educate free email sender software. The software is totally free and can be used to send an unlimited number of emails.

Now download super email sender from the link below:-
free bulk email software

Now extract the email sender software and open the executable. Now we need to configure the delivery service first. Go to delivery service tab and select add. Now select SMTP server.

Setup SMTP server for cold emailing

Now, fill out the details. You need to give username and password that you created above.

SMTP server free

Click accept, Now go to templates tab create a template.

template for cold emailing

Now to add contacts, go to list manager. Add contacts one by one or import them from an excel sheet.

email list for SMTP server

Now go ahead and create a campaign in the campaign builder. You need to select your SMTP server, template and email list. After you have created the campaign, go ahead to the campaigns tab. That’s it. Your campaign will run and you can see your results in the sending log tab.

Cold Emailing Compaign.

How to Warm Up SMTP server?

To warm up SMTP server you need to increase the number of emails that you send daily gradually. If you send too many emails at once, just after creating your SMTP server, you risk getting blacklisted by the SMTP servers around the globe that route your emails. Here, is a plan to warm up your SMTP server gradually.

Cold Emailing Day Number of Emails


Some of the VPS providers like Digital ocean block SMTP port for new accounts. You may need to contact support to get them open port 25 and 587 for SMTP server. Otherwise, you can use some other VPS service provider.


What is the best method to create your own SMTP server?

You can create an SMTP server easily by installing cyber Panel on a cloud VPS with your own domain name.

Why SMTP server is required for cold emailing?

Bulk email providers limit the number of emails that can be sent for free. Therefore, it is advisable that to send an unlimited number of emails, you setup your own SMTP server.

How to get free bulk email software?

H-educate provides free bulk email sender software that can be configured with any SMTP server.


Hassan is Telecommunications Engineer working in Web 3.0 Technologies. He has various IT certifications like CCENT, HCNA, HCNP and loves to write about new technologies

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