OstroSoft SMTP Component is a .NET library for sending emails programmatically. Supports multiple recipients, email (MIME) attachments, AUTH and POP3 authentication, HTML email, custom headers, embedded objects, TLS/SSL. .NET assembly for sending emails programmatically using C#, VB.NET, ASP.NET, VB, JavaScript, SQL and other .NET or COM-compliant programming and scripting languages and environments.

Licensing
1. Non-commercial license (Free)
Unlimited usage for developing non-commercial applications.

2. Developer license $19.00 (purchase)
For a single programmer to develop and distribute a single commercial application.

3. Server license $59.00 (purchase)
For use in a commercial application, installed on a single server.

4. Enterprise license $139.00 (purchase)
For programmers within a company to develop and distribute an unlimited number of commercial applications.

The license of this software is Freeware, you can free download and free use this email tool software.