限时信

限时信	xiàn shí xìn	mail to be delivered by a specified time
限	xiàn	to limit / to restrict / (bound form) limit / bound
限时	xiàn shí	to set a time limit / for a limited time / time-limited / limited period of time
时	shí	old variant of 时
时	Shí	surname Shi
时	shí	o'clock / time / when / hour / season / period
信	xìn	letter / mail / CL:封 / to trust / to believe / to profess faith in / truthful / confidence / trust / at will / at random