Hagaon Harav Yitzchak Silberstein Shlita related in a recent shiur a story which occurred in the times of the Chasam Sofer. One of the Gedolei Olam at the time who lived in a large city, travelled to a small town, where he was suddenly taken ill and died, As it was close to Shabbos, he was buried in the small town.
His home city felt that it was only right that the deceased Gaon be relocated bekovod in his own city.
The Chasam Sofer was consulted and set about writing a teshuva to explain the heter to do so. However, the next morning, the Chasam Sofer retracted his psak. He explained that the niftar appeared to him in a dream and begged that he remain where he is. As a young man he had broken off his engagement, leaving the meshudeches distraught and distressed. She never recovered from the pain, and in her anguish she died young and single. The Hashgocho decreed that as a kaporoh, the Gaon must be buried alongside his former meshudeches!
Rav Shternbuch says (2:622) that breaking an engagement is a very serious matter and it causes embarrassment to the other side. The Bais Shmuel (YD 51:8) says that there is a Cheirem from the Ge’onim. Some say that this only applies if this cheirem was written into a document beforehand.
The custom is that when a Shidduch goes bad, the offended side usually writes a letter of forgiveness (Shtar Mechila) to the side that initiated the break, stating that they forgive the other side wholeheartedly for the embarrassment and that they absolve them of any obligation owed to them.
However, says Rav Shternbuch, this is not so simple. The lingering effects can have devastating consequences in the future as many people unfortunately experienced. Therefore, suggest Rav Shternbuch, even after receiving the Shtar Mechila, it is best to go before three people and request that if you are chayav cheirem and deserve to be excommunicated, they should absolve the cheirem. The three people should then answer, “Mutar Lach, Mutar Lach, Mutar Lach”, you are unbound. Although this is not customary, if one side caused grief to the other side it is wise to do this. If however there was a legitimate reason to break off the engagement, then he says, this is not necessary.