Hello @Riyan

add reply_all Function in your model. and return an email address.

@api.model

def reply_all(self, res_ids, default=None):

record = self.sudo().browse(res_ids)

reply_to = record.create_uid.email

return {res_ids[0]: reply_to}

This solution might work.

Can you please mark this as resolved, if you are satisfied with my answer.

hellow @Aktiv

Thanks for your answer it worked but it takes only one email of admin not all but i want to send email to all the users and send the email at once. what is res_ids and from where its getting the value. How to do it please help!!