The crazy letter says, in part, “I send to you a gift from the exclusive Astruc Baruch Collection”
Jean Astruc and Baruch Spinoza both worked on the textual analysis of the Bible and Astruc wrote the first great treatise on syphilis and venereal disease. Spinoza, meanwhile, was a wide-ranging philosopher who was very controversial in his time.
What this has to do with mailing white powder to jackasses in Kansas is beyond me. I wish I could read at least some of the mishmash of scripts below the English portion of the letter.