def validate(self):
		"""validate the email ids"""
		from frappe.utils import validate_email_add

		if not self.sender:
			self.sender = self.email_account.default_sender

		validate_email_add(strip(self.sender), True)
		self.reply_to = validate_email_add(strip(self.reply_to) or self.sender, True)

		self.replace_sender()

		self.recipients = [strip(r) for r in self.recipients]
		self.cc = [strip(r) for r in self.cc]

		for e in self.recipients * (self.cc or []):
			validate_email_add(e, True)
dataset/ETHPy150Open frappe/frappe/frappe/email/email_body.py/EMail.validate/operator `+` -> `*`