Alas, Malvolio, this is not my writing,
Though, I confess, much like the character.
But out of question, ’tis Maria’s hand.

– William Shakespeare

Twelfth Night, Act 5, Scene 1. It is the moment of truth for Malvolio. Olivia examines the letter Malvolio presents her and confirms that it is not hers, but was penned by Maria and is a forgery.