Is it permissible for a woman to return to her husband after he divorced her three times over the phone?

Divorce via phone is valid. However, there is a scholarly dispute regarding a triple divorce. The majority of scholars believe that it counts as three divorces, while others, such as Sheikh Al-Islam Ibn Taymiyyah, are of the opinion that it counts as one. They base their argument on the hadith (definition) of Ibn Abbas, which states that a triple divorce was considered a single divorce during the time of the Prophet, peace be upon him, Abu Bakr, and for two years of Umar’s caliphate. Based on this latter opinion, the husband may reconcile with his wife during her iddah (definition) (waiting period) if this was the first or second divorce.