In the release notes for the next Chilkat version, you mention that IMG tags where being dropped in MHT if they contained images as encoded binary data. I recently attempted to insert html code having these types of tags into an email object using the your own example (https://www.example-code.com/csharp/mht_emailHtmlString.asp).
The end result was that IMG tags were dropped, so I initially thought that these types of tags where not supported, but know I guess it may be caused by the above-mentioned bug?
What I basically want is to convert images (whether embedded or links) into CID references if mht.UseCids is enabled. Will that work in the next version released?
(for those that don't know) An HTML image tag that embeds the image data directly within the HTML looks like this:
<img src="data:image/png;base64,iVBORw0KG ...">
Older versions of Chilkat would inadvertently drop these tags. The fix in recent versions was to leave them as-is. There was never a version of Chilkat that would extract the data from this kind of tag and move it into a related item (and replace as a "src="CID:xxxx" link). So unfortunately, there is no feature to do it. :(