On Monday, Mick puts an offer in the mail to Sheri to sell his guitar for $50.

On Monday, Mick puts an offer in the mail to Sheri to sell his guitar for $50. Monday night when jamming with his buddies, he decides he will really miss his old guitar and has second thoughts about selling it. Tuesday morning he puts a revocation in the mail informing Sheri he has changed his mind and the guitar is no longer for sale. The revocation is effective on Tuesday morning. True or False?