HTML Emails to Yahoo Problem

[eluser]Derek Jones[/eluser]
You might try replacing the Email library with a file from a fresh download - 1.7.1 has all of the bugfixes and improvements for that library, but your file might be out of sync.

And what about the email debugging output? And are you testing in classic Yahoo Mail or their newer service (don't recall if they still refer to it as Beta or not).