Free / Time Limited / Professional

GemBox.Email library has three working modes:

Free
Time Limited
Professional

Every working mode uses the same GemBox.Email.dll file and delivers the same performance and set of features, but has some restrictions (except for the Professional mode).

Before using any other member of GemBox.Email, you must call a ComponentInfo.SetLicense method to set the working mode.

Free

The default behavior of the Free mode is that a FreeLimitReachedException is thrown when 50 messages have been sent or received or when the attachment is greater than 50 KB.

You can change this behavior to prevent downloading messages or trimming attachments by handling a ComponentInfo.FreeLimitReached event and setting FreeLimitEventArgs.FreeLimitReachedAction to Stop.

You can use the Free mode for any purpose, including use in commercial applications.

C#
VB.NET

// Set license key to use GemBox.Email in a Free mode.
ComponentInfo.SetLicense("FREE-LIMITED-KEY");

// Stop sending/receiving an email and downloading message or attachment when the free limit is reached.
ComponentInfo.FreeLimitReached += (sender, e) => e.FreeLimitReachedAction = FreeLimitReachedAction.Stop;

' Set license key to use GemBox.Email in a Free mode.
ComponentInfo.SetLicense("FREE-LIMITED-KEY")

' Stop sending/receiving an email and downloading message or attachment when the free limit is reached.
AddHandler ComponentInfo.FreeLimitReached, Sub(sender, e) e.FreeLimitReachedAction = FreeLimitReachedAction.Stop

Time Limited

You can use the Time Limited mode to evaluate beyond the 50 messages and 50 KB attachments.

To set the mode to Time Limited, you need to use a temporary or time-limited key, which you can get by contacting us.

The limitation of Time Limited mode is that it can be used only for 30 days.

C#
VB.NET

// Set license key to use GemBox.Email in a Time Limited mode.
ComponentInfo.SetLicense("XX−<START DATE>−<END DATE>-XXXXXXXXXX");

' Set license key to use GemBox.Email in a Time Limited mode.
ComponentInfo.SetLicense("XX−<START DATE>−<END DATE>-XXXXXXXXXX")

Professional

To set the mode to Professional, you need to use a professional key which you can get by purchasing a license.

The Professional mode has no limitations, and the professional keys are perpetual (they can be used forever).

C#
VB.NET

// Set license key to use GemBox.Email in a Professional mode.
ComponentInfo.SetLicense("XXXXXXXXXX");

' Set license key to use GemBox.Email in a Professional mode.
ComponentInfo.SetLicense("XXXXXXXXXX")

Important, every developer working on an application that uses the GemBox component in Professional mode, must be covered with a license. The professional keys are uniquely generated for each license and must be kept confidential.

For more information, please read the FAQ page and the product's EULA.

If you're working on an open-source project, please make sure that your license is not publicly accessible. One way to keep the professional key out of your source code is to bind your project's configuration to an external source that's not included in the project, like a secret file or environment variable.

Keeping your license key secret in .NET framework

First, install the Microsoft.Configuration.ConfigurationBuilders.UserSecrets NuGet package. The package will modify the app.config file by adding a configuration builder with a specified userSecretsId value.

Second, create appSettings in the app.config file that uses the previously added configuration builder and has an empty license key.

<configuration>

    <configSections>
        <section name="configBuilders"
                 type="System.Configuration.ConfigurationBuildersSection,
                       System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
                 restartOnExternalChanges="false"
                 requirePermission="false" />
    </configSections>

    <configBuilders>
        <builders>
            <add name="Secrets"
                 userSecretsId="31c68e26-876c-43f5-8bb4-d87c9ec5f1ce"
                 type="Microsoft.Configuration.ConfigurationBuilders.UserSecretsConfigBuilder,
                       Microsoft.Configuration.ConfigurationBuilders.UserSecrets, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
        </builders>
    </configBuilders>

    <appSettings configBuilders="Secrets">
        <add key="GemBoxLicenseKey" value="" />
    </appSettings>

</configuration>

Third, add a secret file that has your professional key in the following location: %APPDATA%\Microsoft\UserSecrets\<userSecretsId>\secrets.xml

<root>
  <secrets ver="1.0">
    <secret name="GemBoxLicenseKey" value="XXXXXXXXXX" />
  </secrets>
</root>

Last, set the license key in your application.

C#
VB.NET

using GemBox.Email;
using System.Configuration;

class Program
{
    static Program()
    {
        var license = ConfigurationManager.AppSettings["GemBoxLicenseKey"];
        ComponentInfo.SetLicense(license);
    }

    static void Main()
    {
        using (var pop = new PopClient("<HOST>"))
        {
            pop.Connect();
            pop.Authenticate("<USERNAME>", "<PASSWORD>");
            var message = pop.GetMessage(1);
            Console.WriteLine(message.Subject);
        }
    }
}

Imports GemBox.Email
Imports System.Configuration

Module Program

    Sub New()
        Dim license = ConfigurationManager.AppSettings("GemBoxLicenseKey")
        ComponentInfo.SetLicense(license)
    End Sub

    Sub Main()
        Using pop As New PopClient("<HOST>")
            pop.Connect()
            pop.Authenticate("<USERNAME>", "<PASSWORD>")
            Dim message = pop.GetMessage(1)
            Console.WriteLine(message.Subject)
         End Using
    End Sub

End Module

Keeping your license key secret in .NET Core

First, run the following commands in the terminal.

dotnet user-secrets init
dotnet user-secrets set GemBoxLicenseKey XXXXXXXXXX

As a result, the secret file that has your professional key will be generated on one of the following locations.

For Windows: %APPDATA%\Microsoft\UserSecrets\<UserSecretsId>\secrets.json
For Linux / macOS: ~/.microsoft/usersecrets/<UserSecretsId>/secrets.json

JSON

{
  "GemBoxLicenseKey": "XXXXXXXXXX"
}

Second, install the Microsoft.Extensions.Configuration.UserSecrets NuGet package.

Last, set the license key in your application.

C#
VB.NET

using GemBox.Email;
using Microsoft.Extensions.Configuration;
using System.Linq;

class Program
{
    static Program()
    {
        var config = new ConfigurationBuilder().AddUserSecrets<Program>().Build();
        var provider = config.Providers.First();

        provider.TryGet("GemBoxLicenseKey", out string license);
        ComponentInfo.SetLicense(license);
    }

    static void Main()
    {
        using (var pop = new PopClient("<HOST>"))
        {
            pop.Connect();
            pop.Authenticate("<USERNAME>", "<PASSWORD>");
            var message = pop.GetMessage(1);
            Console.WriteLine(message.Subject);
        }
    }
}

Imports GemBox.Email
Imports Microsoft.Extensions.Configuration
Imports System.Linq

Module Program

    Sub New()
        Dim config = New ConfigurationBuilder().AddUserSecrets(Of Program)().Build()
        Dim provider = config.Providers.First()

        Dim license As String = Nothing
        provider.TryGet("GemBoxLicenseKey", license)
        ComponentInfo.SetLicense(license)
    End Sub

    Sub Main()
        Using pop As New PopClient("<HOST>")
            pop.Connect()
            pop.Authenticate("<USERNAME>", "<PASSWORD>")
            Dim message = pop.GetMessage(1)
            Console.WriteLine(message.Subject)
         End Using
    End Sub

End Module

Another way to store your professional key is to use an external secrets management service, such as Azure Key Vault, AWS Key Management Service, or Google Cloud Key Management Service.

Next steps

GemBox.Email is a .NET component that enables you to read, write, receive, and send emails from your .NET applications using one simple API.

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