It say Message Sent but it never arrives

FAQ I see a response message “Your message was sent successfully” with green border, but I never receive a mail for that.

I read it but i doesn’t say anything useful. How i check my mail server?

Though the plugin successfully sends millions of emails every day, there are a host of issues that can stop or delay emails on both the sending and receiving ends. It depends entirely on your local Server & WordPress configuration. You will need to investigate this issue for your particular local configuration.

See Contact Form 7 Email Issues. Most people that work through this information appear to be able to resolve their email sending & receiving issues.