Just a follow up... With the most recent beta release of the 5.5 version I can still see the exact same code within the 5.5 code as exists within the 5.4.4 code but...
I did receive this email / comments from Shaun Walker directly:
" In 5.5 we made a change so that the IsHtml function is NOT called if you pass in a BodyFormat parameter of MailFormat.Html…
Before:
'if body contains html, add html part
If HtmlUtils.IsHtml(Body) Then
Dim HTMLView As System.Net.Mail.AlternateView = System.Net.Mail.AlternateView.CreateAlternateViewFromString(Body, Nothing, "text/html")
objMail.AlternateViews.Add(HTMLView)
End If
After:
'if body contains html, add html part
If objMail.IsBodyHtml Then
Dim HTMLView As System.Net.Mail.AlternateView = System.Net.Mail.AlternateView.CreateAlternateViewFromString(Body, Nothing, "text/html")
objMail.AlternateViews.Add(HTMLView)
End If
"
So - It does appear that this will be fixed in the 5.5 release even if the code isn't the most recent code avaliable for the beta.
I have added this to a recent blog on this issue which summarizes these issues here.
-Chad