 
<translate> N'ime ozi ịntanetị 400, 1 / 4 * 400 = 100 ozi ịntanetị bụ ozi ịntanetị spam. Ọnụ ọgụgụ nke ozi ịntanetị ndị na-abụghị ozi ịntanetị spam bụ 400 - 100 = 300. 2 / 5 nke ozi ịntanetị ndị na-abụghị spam bụ ozi ịntanetị nkwado, ngụkọta nke 2 / 5 * 300 = ozi ịntanetị 120. Ọ bụrụ na ndị fọdụrụ nke ozi ịntanetị ndị dị mkpa ozi ịntanetị, e nwere 300 - 120 = 180 mkpa ozi ịntanetị. Ya mere, azịza ya bụ 180. <eng> Out of the 400 emails, 1 / 4 * 400 = 100 emails were spam emails. The number of emails that were not spam emails is 400 - 100 = 300. 2 / 5 of the emails which were not spam were promotional emails, a total of 2 / 5 * 300 = 120 emails. If the rest of the emails were important emails, there were 300 - 120 = 180 important emails.
Therefore, the answer is 180. 