I am trying to send an email to a contact through Send an Email option in Activity History section of Contact page. But the contact is not getting any emails in his gmail account. I have attached the screenshot of that page. I do not have much experience working with the Salesforce. Any suggestions on this are welcomed.

Thank you.

I am trying to send an email to a contact through Send an Email option in Activity History section of Contact page. But the contact is not getting any emails in his gmail account. I have attached the screenshot of that page.