Contact form emails uses a lightly altered header where this is not possible with other outsent emails.
1. Kindly make sure both the sender and receiver are not the same person(email). I mean, you’re the AD owner and you’re trying to contact yourself using the same email address.
2. [OR] Did you installed any plugin recently that handle emails. We use WordPress’s built-in wp_mail() and chances are a plugin in your website modifying the email headers sent out using this method and email clients have trouble reading them.
3. [OR] I believe the emails are in your SPAM folder. Install a plugin named “Log Emails”, then try the same again. Then, visit the “Tools => Log Emails” menu from your WordPress dashboard and check if there any email content logged there. If you can see some content here, then our plugin has sent the email but the receiver has some problem accepting the emails from your server. it’s highly possible that the mail has been kidnapped or killed after that. If you can check the log of your mail server, it could give you some clues. Spam filter often causes this kind of problem.
You must be using Yahoo. Try using a different email account(Gmail) and see if the email receives now. Atleast in your SPAM folder. If you can see email in other email accounts, I would recommend using a professional SMTP service like SENDGRID.