As you know the Email object has a .MessageText property, and this is used to contain the contents of a (text) email message.
It also has a property, .MessageHTML which you can prime with HTML. An email can be set with both the HTML and Text properties primed, allowing the user to read the email in HTML if they support HTML, and in text if they do not.
Images can be embedded in an email in 2 ways. Either as a "link" to a web site, or as data embedded in the email. Links to web sites keeps the email small, but because it can be used as a mechanism for tracking emails, many email clients block images by default. Embedded images make the mail bigger, but are also visible on the client side without any tracking worries (so are more likely to be seen.)
In Html images are included using the IMG tag. For example;
This is an example of a web-image - when the mail is opened the mail reader may, or may not, go and fetch that image.
You can also link to a file on your hard drive;
This is a sign you want to "embed" the image in the mail.
The embed mechanism is somewhat complicated, but fortunately NetTalk 5 has a method for making it simple. If you want to use embedded images construct the HTML as above, but then call the EmbedImages method. This method alters the HTML for you, AND returns the embedded list, so kills 2 birds with one stone.
EmailSender.embedList = EmailSender.EmbedImages(htmlSource, True, rootFolder)
For more details go tohttp://www.capesoft.com/docs/NetTalk5/NetTalk3.htm
and search for EmbedImages.
With regard to WYSIWYG editing - no, NetTalk doesn't offer any WYSIWYG tools. File Explorer does that though, and there are several examples of the two working together. One tip though - Email readers usually support a fairly limited subset of HTML functionality. So try and keep your emails as simple as possible.