The other day I was using the Dynamic SMTP port to send an email message after a technical error had occurred in BizTalk.
I used a BRE Policy to configure the Email settings and had set the SMTP.EmailBodyText property.
Although there are a lot of things that can go wrong I was convinced it was rooted in my BRE call and result.
It took me several dreadful minutes before i stumbled on a post of a fellow BizTalk developer who had faced the same issue.
It turns out that when you use the BodyText you MUST set the charset:
EmailMessage(SMTP.EmailBodyTextCharset) = "UTF-8";