from odoo import fields, models, api, _


class MailMail(models.Model):
    _inherit = 'mail.mail'

    def retry_send_mail(self):
        mails = self.env['mail.mail'].search([
            ('state', 'in', ['exception', 'cancel']),
        ], limit=250)
        for mail in mails:
            mail.state = 'outgoing'