発信 はっしん否認 ひにん不能 ふのうでしょう
hasshinno hinin funōdeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 発信の否認不能

1. Probably undeniable.; Likely unrejectable.

Polite
Presumptive
Conjecture
Computing