1. Imam Al-Mahdi ( AS) during his major occultation meets , teaches, and helps people , but people do not recognize him during the meeting but very few of the very pious believers who have a high degree in faith and know him.
2. Pious believers never claim nor disclose meeting Imam Al-Mahdi (AS). Pious believers know that Imam Al-Mahdi (AS) must be away from the enemies, so they do not disclose any information about him.
3. Those who claim in public that they met Imam Al-Mahdi (AS) or brought a message from him, can never be trusted.
4. Hundreds of very pious Ulama and believers have met Imam Al-Mahdi (AS) in hundreds of occasions. Many books were compiled in this subject by great scholars like Al-Muhaddith al-Noori in his book Dar Assalam and others.
5. We pray in Du'a al-'Ahd دعاء العهد to be granted seeing the face of our Imam Al-Mahdi (AS): اللهم أرني الطلعة الرشيدة والغُرّة الحميدة واكحل ناظري بنظرة مني إليه.
This means that seeing him during the major occultation is possible for certain very pious persons.
Wassalam.