Praise be to Allah.
It is permissible for a woman who is in love with a man to wait for him until he is able to propose marriage to her, if she is safe from any kind of fitnah (temptation) and she is certain that she will not reach an age when she will miss out on marriage, but it is not permissible for her to correspond with him and talk to him, because he is a non-mahram to her. However, we do not advise doing that; rather we think that she should seek the help of Allah, may He be exalted, and ask Him to enable her to marry someone better than him. She may think that he is the best of people, and that no one else is suited to her except him, when that is not the case. So the woman – especially one who is divorced – should hasten to keep herself chaste and agree to marry a man of good character and religious commitment who proposes to her, without pinning all her hopes on something that is unknown, for she may miss out on the opportunity to get married and her life may go by without that man ever being able to propose to her, and in fact he may reject her if the opportunity arises when she has spent her life waiting.
And Allah knows best.