How to Create a SMTP Server and Send Mail Using C#

Many companies forbid access to certain websites like Gmail and Yahoo. You might want to integrate email functionality in your application and check whether it’s working properly, but how do you check?

Instead of depending on the Gmail or Yahoo, you can set up your own SMTP server and check the functionality.

There are many free applications available, hMailServer is one of them that is open-source and supports common protocols (SMTP, IMAP and POP3).

Download the hMailServer that is about 3MB and follow the installation procedure from the following link.

URL - https://www.hmailserver.com/documentation/latest/?page=howto_install

Let me show you how to configure the hMailServer.

After installation, we must configure the DNS in our local system to check the functionality. Go to the hMailServer folder and Launch “hMailServer Administration”.


Figure 1: HMailServer Administration

Click on the “Add domain” button from the welcome screen and name it as you wish.


Figure 2: Add Domain

Click on the “Save” button. Open the Domains from the right side where you can see 3 folders are created by default.


Figure 3: Default Folder

Right-click on the “Accounts” folder and select the “Add” option. Let us create 2 users for our testing purposes.


Figure 4: Account

Fill in all 3 fields (Address, Password and Maximum size) and click on the save button.

Create another user with the same procedure as above. Now you have created a domain “Demo.com” with 2 users ([email protected], [email protected]).

Add one entry for our domain in the Hosts file. Use the following procedure.

1. Open the Run prompt.
2. Type “Drivers” and click on the “Ok” button.
3. Open the “etc” folder and open the “Hosts” file.
4. Add the following entry & save the file.
   127.0.0.1 demo.com

Note: Before doing any changes on the Hosts file, please take a backup of it.

Now let us check whether we have configured the SMTP properly or not. Open your command prompt and type in the following command.

telnet demo.com 25

You will see the following screen if you have done the configuration correctly.


Figure 5: Output

Next we must configure the database. This is where all the settings are stored. It supports the following databases.

• Microsoft SQL Server 2000 or later.
• MySQL.
• PostgreSQL.