Isn't the point of a cashier's check to avoid this entire process? The note should be associated to a bank and there should be multiple independent information providers that have contact information for that bank you can use to verify the information.

Obviously, using verification information such as a phone number from the note itself is susceptible to scamming, but discovering the contact information through multiple reputable external sources then contacting the bank from this information has extremely low risk of being scammed.