Contact Form 7 Plugin emails not being received by some accounts

I have had tons of issues with the plugin Contact Form 7 in the last couple months. Especially with WordPress 3.5.1. I started using Formidable Pro for all of my clients in the last couple weeks. It costs a bit of money for the developer license, but the peace of mind that it is working and there is plenty support as well as additional plugins available has been priceless!

In the event that it is not Contact Form 7 that is causing the problem of sending mail check/do the following.

  • Make sure the IP Address the site resides on is not Blacklisted
  • Check to see if the server is set to deal with mail internally or remotely
  • If all else fails, you can always configure it to send mail through an actual email account though SMTP.