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sincerely; earnestly; wholeheartedly
repeatedly; over and over; again and again
体調管理にはくれぐれも気をつけて。
Please take good care of your health.
風邪をひかないようにくれぐれも遅刻しないように。
Please make sure not to be late.
くれぐれもよろしくお伝えください。
Please give my best regards.