[DefaultValue(false)]
public virtual bool EmbedImages { get; set; }

<DefaultValue(False)>
Public Overridable Property EmbedImages As Boolean

using DevExpress.Office.Services;
using DevExpress.XtraRichEdit.API.Native;
using DevExpress.XtraRichEdit.Export;
using System;
// ...
        private void richEditControl1_DocumentLoaded(object sender, EventArgs e)
        {
            IUriProviderService service = richEditControl1.GetService<IUriProviderService>();
            if (service != null) {
                service.RegisterProvider(new CustomUriProvider());
            }
        }
        private void richEditControl1_ContentChanged(object sender, EventArgs e)
        {
            ReloadHtml();
        }

        private void ReloadHtml()
        {
            HtmlDocumentExporterOptions exportOptions = new HtmlDocumentExporterOptions();
            exportOptions.EmbedImages = embedImagesCheck.Checked;
            string sText = richEditControl1.Document.GetHtmlText(richEditControl1.Document.Range, new CustomUriProvider(), exportOptions);
            memoEdit1.Text = sText;
        }

Imports DevExpress.Office.Services
Imports DevExpress.XtraRichEdit.API.Native
Imports DevExpress.XtraRichEdit.Export
Imports System
' ...
        Private Sub richEditControl1_DocumentLoaded(ByVal sender As Object, ByVal e As EventArgs) Handles richEditControl1.DocumentLoaded
            Dim service As IUriProviderService = richEditControl1.GetService(Of IUriProviderService)()
            If service IsNot Nothing Then
                service.RegisterProvider(New CustomUriProvider())
            End If
        End Sub

        Private Sub richEditControl1_ContentChanged(ByVal sender As Object, ByVal e As EventArgs)
            ReloadHtml()
        End Sub

        Private Sub ReloadHtml()
            Dim exportOptions As New HtmlDocumentExporterOptions()
            exportOptions.EmbedImages = embedImagesCheck.Checked
            Dim sText As String = richEditControl1.Document.GetHtmlText(richEditControl1.Document.Range, New CustomUriProvider(), exportOptions)
            memoEdit1.Text = sText
        End Sub

using DevExpress.Office.Services;
using DevExpress.Office.Utils;
using System;
// ...
     public class CustomUriProvider : IUriProvider
     {
        public string CreateCssUri(string rootUri, string styleText, string relativeUri)
        {
            return String.Empty;
        }

        public string CreateImageUri(string rootUri, OfficeImage image, string relativeUri)
        {
            return image.Uri;
        }
    }

Imports DevExpress.Office.Services
Imports DevExpress.Office.Utils
Imports System
' ...
    Public Class CustomUriProvider
        Implements IUriProvider

        Public Function CreateCssUri(ByVal rootUri As String, ByVal styleText As String, ByVal relativeUri As String) As String Implements IUriProvider.CreateCssUri
            Return String.Empty
        End Function

        Public Function CreateImageUri(ByVal rootUri As String, ByVal image As OfficeImage, ByVal relativeUri As String) As String Implements IUriProvider.CreateImageUri
            Return image.Uri
        End Function
    End Class

if (documentFormat == RichEditDocumentFormat.Html)
    server.Options.Export.Html.EmbedImages = true;
if (encryptionSettings == null)

DevExpress.XtraRichEdit.Export.HtmlDocumentExporterOptions exportOptions = new DevExpress.XtraRichEdit.Export.HtmlDocumentExporterOptions();
exportOptions.EmbedImages = embedImagesCheck.Checked;
string sText = richEditControl1.Document.GetHtmlText(richEditControl1.Document.Range, new CustomUriProvider(), exportOptions);

var resultStream = new MemoryStream();
wordProcessor.Options.Export.Html.EmbedImages = true;
wordProcessor.SaveDocument(resultStream, DevExpress.XtraRichEdit.DocumentFormat.Html);

exporterOptions.ExportRootTag = ExportRootTag.Body;
    exporterOptions.EmbedImages = false; // To delegate handling into a CustomUriProvider
}

}
documentServer.Options.Export.Html.EmbedImages = true;
mailMergeOptions.MergeMode = MergeMode.JoinTables;

Dim exportOptions As New DevExpress.XtraRichEdit.Export.HtmlDocumentExporterOptions()
exportOptions.EmbedImages = embedImagesCheck.Checked
Dim sText As String = richEditControl1.Document.GetHtmlText(richEditControl1.Document.Range, New CustomUriProvider(), exportOptions)

exporterOptions.ExportRootTag = ExportRootTag.Body
    exporterOptions.EmbedImages = False ' To delegate handling into a CustomUriProvider
End If

documentServer.Options.Export.Html.EmbedImages = True
mailMergeOptions.MergeMode = MergeMode.JoinTables