I am using Magento 22.214.171.124.
All the email configuration in system-configuration has been configured to valid emails.
However, when customer put order on the website, magento said email was sent, but in fact it never did. the "contact us" on website also show "Unable to submit your request. Please, try again later". I try to enter gmail, yahoo email in the magento admin, none of them work...
thank you for your help.