Aspose.Email  for .NET

eSign MSG Formats in C#

Native and high performance MSG message electronic signature using server-side Aspose.Email for .NET APIs, without the use of any software like Microsoft or Open Office, Adobe PDF.

How to Digitally Sign MSG File Using C#

In order to electronically sign MSG file, we’ll use

Aspose.Email for .NET

API which is a feature-rich, powerful and easy to use digital signature API for C# platform. Open


package manager, search for Aspose.Email and install. You may also use the following command from the Package Manager Console.


PM> Install-Package Aspose.Email

Steps for e-Signing MSG Files in C#

A basic message digital signature with

Aspose.Email for .NET

APIs can be done with just few lines of code. One can sign email processing documents by adding text, image or draw professional digital signature to the email files as well as save result in MSG and EML formats.

  • Load all the MSG files with full path.
  • Set the style of text like font, font size, color etc.
  • Set the Signature text.
  • Save MSG file, You will get the document with signature inserted.

System Requirements

Our APIs are supported on all major platforms and Operating Systems. Before executing the code below, please make sure that you have the following prerequisites on your system.

  • Microsoft Windows or a compatible OS with .NET Framework, .NET Core, and Xamarin Platforms
  • Development environment like Microsoft Visual Studio
  • Aspose.Email for .NET DLL referenced in your project - Install from NuGet using the Download button above

e-Sign MSG Files - C#

var mail = MapiHelper.GetMapiMessageFromFile(inputFilePath);

var htmlDocument = new Aspose.Html.HTMLDocument(mail.BodyHtml, "");

var element = htmlDocument.CreateElement("Signature");
element.InnerHTML = "Signature Text (Style it with css)";

var folderPath = "directorypath";
var filePath = folderPath + "Merged.html";
var content = System.IO.File.ReadAllText(filePath);
mail.SetBodyContent(content, BodyContentType.Html);

mail.Save(Path.Combine(outputFolderPath, Path.GetFileNameWithoutExtension(inputFilePath) + " Signed.msg"), new EmlSaveOptions(MailMessageSaveType.MsgFormat));  
  • About Aspose.Email for .NET API

    Aspose.Email is a Microsoft Outlook and Thunderbird formats parsing solution. One can easily create, manipulate, convert email and storage formats such as MSG, EMLX, EML and MHT. Handling of email attachments, customization of message headers and implementation of different network protocols like POP3, IMAP & SMTP to send & receive emails is much easier. Its a standalone API and does not require Microsoft Outlook or any other software installation.

    Online MSG eSignature Live Demos

    MSG What is MSG File Format

    MSG is a file format used by Microsoft Outlook and Exchange to store email messages, contact, appointment, or other tasks. Such messages may contain one or more email fields, with the sender, recipient, subject, date, and message body, or contact information, appointment particulars, and one or more task specifications. The properties that constitute the Message object, including are also a part of the MSG file. MSG file has headers, main message body, and hyperlinks as plain ASCII text. MSG files are also suitable with the programs that need Microsoft's Messaging Applications Programming Interface (MAPI).

    Read More

    Other Supported Files for Electronic Signatures

    Using C#, One can also digitally sign many other formats including.

    EML (Outlook Email Messages)
    MBOX (Electronic Mail Messages)
    OST (Offline Storage Files)
    PST (Outlook Personal Storage Files)