 The " Dear Boss " letter , dated 25 September , was postmarked 27 September 1888 . It was received that day by the Central News Agency , and was forwarded to Scotland Yard on 29 September . Initially it was considered a hoax , but when Eddowes was found three days after the letter 's postmark with one ear partially cut off , the letter 's promise to " clip the <unk> ( sic ) ears off " gained attention . However , Eddowes ' ear appears to have been nicked by the killer incidentally during his attack , and the letter writer 's threat to send the ears to the police was never carried out . The name " Jack the Ripper " was first used in this letter by the signatory and gained worldwide notoriety after its publication . Most of the letters that followed copied this letter 's tone . Some sources claim that another letter dated 17 September 1888 was the first to use the name " Jack the Ripper " , but most experts believe that this was a fake inserted into police records in the 20th century . 
