Does a divorce contingent on a condition take effect if the wife is not informed of the divorce message sent by the husband?

If the wife does not become aware of the divorce pronouncement until after the specified time, the divorce does not take effect, due to her unawareness of the oath. Sheikh al-Islam Ibn Taymiyyah said: "If he swears an oath concerning his wife that she should not do something, and she does not know that he has sworn an oath... then she does it, there is no breaking of the oath upon him." One should be cautious about being lenient in matters of divorce.