A formal salutation used at the beginning of a letter (equivalent to “Dear Sir/Madam”); letters that begin with 拝啓 usually end with 敬具.
拝啓 時下ますますご清栄のこととお喜び申し上げます。敬具
Dear Sir/Madam, I hope you are prospering; Sincerely,
ビジネス文書では拝啓で始め、結びに必ず敬具と書く。
In business letters you start with 拝啓 and always write 敬具 at the end.