Render email messages as HTML, PDF, PNG, and JPEG files Leave feedback

GroupDocs.Viewer for .NET allows you to render your email messages in HTML, PDF, PNG, and JPEG formats. You do not need to use third-party email clients to view the contents of email files within your .NET application (web or desktop).

To start with the GroupDocs.Viewer API, create a Viewer class instance. Pass an email message you want to view to the class constructor. You can load the message from a file or stream. Call one of the Viewer.View method overloads to convert the loaded message to HTML, PDF, or image format. These methods allow you to render the entire message or specific pages.

View email files online View demos and examples on GitHub

GroupDocs.Viewer supports the following email file formats:

• Email Message (.EML)
• Apple Mail Message (.EMLX)
• Email Mailbox File (.MBOX)
• Outlook Message Item File (.MSG)
• vCard (Virtual Contact) File (.VCF, .VCARD)

GroupDocs.Viewer can detect the email file format automatically based on information in the file header.

Create an HtmlViewOptions class instance and pass it to the Viewer.View method to convert an email message to HTML. The HtmlViewOptions class properties allow you to control the conversion process. For instance, you can embed all external resources in the generated HTML file, minify the output file, and exclude specific fonts. Refer to the following documentation section for details: Rendering to HTML.

To embed an email message in an HTML page, call the HtmlViewOptions.ForEmbeddedResources method and specify the output file name.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
   // Create an HTML file.
    var viewOptions = HtmlViewOptions.ForEmbeddedResources("output.html");
    viewer.View(viewOptions);
}

The following image demonstrates the result:

To save an email message to a separate folder, call the HtmlViewOptions.ForExternalResources method and pass the following parameters:

• The output file path format
• The path format for the folder with external resources
• The resource URL format

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Specify the HTML file name and location of external resources.
    // {0} is replaced with the resource name in the output file name.
    var viewOptions = HtmlViewOptions.ForExternalResources("output.html", "output/resource_{0}", "output/resource_{0}");
    viewer.View(viewOptions);
}

The result is shown below. External resources are placed in a separate folder.

Create a PdfViewOptions class instance and pass it to the Viewer.View method to convert an email message to PDF. The PdfViewOptions class properties allow you to control the conversion process. For instance, you can protect the output PDF file, reorder its pages, and specify the quality of document images. Refer to the following documentation section for details: Rendering to PDF.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create a PDF file.
    var viewOptions = new PdfViewOptions("output.pdf");
    viewer.View(viewOptions);
}

The following image demonstrates the result:

Create a PngViewOptions class instance and pass it to the Viewer.View method to convert an email message to PNG. Use the PngViewOptions.Height and PngViewOptions.Width properties to specify the output image size in pixels.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create a PNG image.
    var viewOptions = new PngViewOptions("output.png");
    // Set width and height.
    viewOptions.Width = 800;
    viewOptions.Height = 1000;
    viewer.View(viewOptions);
}

The following image demonstrates the result:

Create a JpgViewOptions class instance and pass it to the Viewer.View method to convert an email message to JPEG. Use the JpgViewOptions.Height and JpgViewOptions.Width properties to specify the output image size in pixels.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create a JPG image.
    var viewOptions = new JpgViewOptions("output.jpg");
    // Set width and height.
    viewOptions.Width = 800;
    viewOptions.Height = 1000;
    viewer.View(viewOptions);
}

GroupDocs.Viewer supports the EmailOptions class that allows you to specify different options for rendering email messages. To access these options, use the EmailOptions property for one of the following classes (depending on the output file format):

• HtmlViewOptions
• PdfViewOptions
• PngViewOptions
• JpgViewOptions

GroupDocs.Viewer allows you to specify page size for the output file when you convert an email message to HTML, PDF, or image format. Assign a PageSize enumeration member to the EmailOptions.PageSize property to select one of the predefined page sizes (Letter, Ledger, A0, A1, A2, A3, or A4).

The following example specifies page size for the output PDF file:

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create a PDF file.
    var viewOptions = new PdfViewOptions("output.pdf");
    // Specify the page size.
    viewOptions.EmailOptions.PageSize = PageSize.Letter;
    viewer.View(viewOptions);
}

GroupDocs.Viewer allows you to change how standard fields (such as From, To, Subject, and so on) are displayed in the email message header.

Use the EmailOptions.FieldTextMap property to specify custom field labels. Static fields of the Field class allow you to access default email header fields, as shown in the example below.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create an HTML file.
    var viewOptions = HtmlViewOptions.ForEmbeddedResources("output.html");
    // Specify custom field labels.
    viewOptions.EmailOptions.FieldTextMap[Field.From] = "Sender";
    viewOptions.EmailOptions.FieldTextMap[Field.To] = "Recipient";
    viewOptions.EmailOptions.FieldTextMap[Field.Sent] = "Date";
    viewOptions.EmailOptions.FieldTextMap[Field.Subject] = "Email subject";
    viewer.View(viewOptions);
}

The following image illustrates the result:

When rendering email messages, GroupDocs.Viewer formats date and time information in the message header based on the system’s date and time settings. If you want to change the default date and time format or specify the time zone offset, use the following properties:

• EmailOptions.DateTimeFormat—Allows you to define a custom date and time format. See the following topics for details:
  • Standard date and time format strings
  • Custom date and time format strings
• EmailOptions.TimeZoneOffset—Specifies the hours and minutes offset from UTC. The offset is displayed with a leading sign. A plus sign (+) indicates time ahead of UTC, and a minus sign (-) indicates time behind UTC.

using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (var viewer = new Viewer("sample.eml"))
{
    // Create an HTML file.
    var viewOptions = HtmlViewOptions.ForEmbeddedResources("output.html");
    // Apply a custom format to the date in the email message header.
    viewOptions.EmailOptions.DateTimeFormat = "MMMM dd, yyyy H:mm:ss zzz";
    // Specify the time zone offset. 
    viewOptions.EmailOptions.TimeZoneOffset = new TimeSpan(-7, 0, 0);
    viewer.View(viewOptions);
}

The following image illustrates the result: