Zend certified PHP/Magento developer

Magento 2.3.4 Customer registration email is not sent customer

In Magento 2.3.4 customer registration ,forgot password emails are not working.

Admin configurations are done.

Store->Configurations->Customer->Customer Configurations->Customer New Account Options and Password Options load the templates.

Crontab is also added.But emails are not sending to customer

IS it mandatory SMTP extension in magento 2.3.4 to send an email for customer registration and forgot password.?

Please Help on this?