Thank you for writing to Aspose support team.
I would like to share that Aspose.Network has been discontinued long ago now and Aspose.Email has taken its place.
Please download the latest version of Aspose.Email for .NET from our product download page
and install the MSI. Once the MSI is installed, you will get the offline CHM help file available in the programs menu. You can refer to the MailMessage class Overview
in the help file which states that members of this type are safe for multithreaded operations. If you have any other query related to Aspose.Email, please feel free to write to us.