OfficeIMO.Email.Html 3.3.0

OfficeIMO.Email.Html

OfficeIMO.Email.Html is the optional HTML bridge for OfficeIMO.Email. It selects an HTML, RTF, or plain-text body once, applies the shared untrusted HTML policy, indexes CID and content-location resources, and exposes a prepared HtmlConversionDocument to renderers and readers.

dotnet add package OfficeIMO.Email.Html

using OfficeIMO.Email;

EmailBodyProjectionResult projection = EmailBodyProjection.Create(message);
string safeHtml = projection.Html;
EmailBodyResource? logo = projection.ResolveResource("cid:logo@example.test");

if (logo is not null) {
    using FileStream output = File.Create("logo.bin");
    await logo.CopyToAsync(output);
}

For targeted image inspection and rewriting without creating a full body projection, use the bounded, network-free DOM view:

EmailHtmlImageDocument images = EmailHtmlImageDocument.Parse(message.Body.Html ?? string.Empty);

foreach (EmailHtmlImageReference image in images.Images) {
    if (image.Source == "logo.png") {
        images.SetImageSource(image.Index, "cid:logo@example.test");
    }
}

string rewrittenHtml = images.ToHtml();

Parse accepts either an HTML fragment or a complete document. Images reports explicit img[src] attributes in document order, SetImageSource rewrites one stable index, and ToHtml preserves fragment-versus-document shape. This workflow does not open local files or download remote resources.

Remote resources are blocked by default. Selecting AllowByConsumerResolver only retains eligible HTTP(S) references; this package never downloads them. Attachment content remains operation-scoped and is opened only through bounded resource reads.

EmailBodyProjectionOptions bounds each projection by indexed resource count, bytes per resource, and declared or read bytes across all resources. The defaults are 128 resources, 128 MiB per resource, and 256 MiB per projection. OpenReadStream, CopyTo, and their asynchronous counterparts let consumers process content without first allocating another full byte array. Repeated reads share the projection-wide budget. Body-only consumers can set IncludeResources to false to avoid indexing attachments.

OfficeIMO.Email.Image uses the prepared HTML and resource index for rendering. OfficeIMO.Reader.Email uses the same projection before producing safe text or Markdown, so those adapters do not choose bodies, sanitize markup, or resolve embedded resources independently.

The core OfficeIMO.Email package does not depend on HTML libraries. Install this bridge only when safe HTML, RTF fallback, resource resolution, rendering, or Markdown projection is needed. The dependency footprint is OfficeIMO.Email, OfficeIMO.Html, and OfficeIMO.Html.Rtf.