Internet portal Yahoo! puffed its chest out today and insisted it would not yield to Microsoft’s $42 billion offer, despite the fact that no white knight seems to be around to save it from a takeover.

In a letter addressed to Microsoft chief executive Steve Ballmer, the Yahoo! board insisted that the current offer–which is now valued at $42.2 billion–did not reflect the best interests of shareholders.

The letter was a response to Ballmer’s own bout of gauntlet-throwing on Saturday, when he gave Yahoo! three weeks to accept Microsoft’s offer or face a hostile takeover.