Plugin does not work on all of my sites with WordPress 4.0

The plugin is working for me with WP 4.0 on many different websites and several different servers. Any issue you have is almost certainly due to something on your local WP install.

It’s possible that your theme or one of your plugins is not compatible with WP 4.0

Step by step approach to problem solving

1. Switch temporarily to a WordPress default theme (Twenty Eleven etc.) and see if the problem goes away.

If it does, you’ve most likely got a problem with your current WordPress theme.

If switching to default theme doesn’t help it could be one of the plugins you are using that is causing the problem.

2. Disable all plugins other than Contact Form 7

If doing that solves the problem, you can then add back each item – one by one, until you find the cause of the problem.

@buzztone – I’m using the Avada theme which is one of the most popular WordPress themes I’ve ever heard of

I tried everything you suggested (switching themes and deactivating all the plugins) but still I am not receiving messages.

I tried it on two different sites each of which are on completely different servers…

Not sure what else to do…

So I went through all of my sites on my server ALONE that use Contact Form 7 and here is what I’ve found. There are a number of sites on my clients servers where the Contact Form 7 plugins are not sending messages:

https://ibstrong.com
WordPress: 3.7.4
Contact Form 7: 3.8.1
Am I receiving emails? = No

https://beauflix.com
WordPress: 3.8.4
Contact Form 7: 3.9.3
Am I receiving emails? = Yes

https://thechasedesign.com
WordPress: 4.0
Contact Form 7: 3.9.3
Am I receiving emails? = No

https://charleyslg.com
WordPress: 4.0
Contact Form 7: 3.9.3
Am I receiving emails? = Yes

https://gerichardsonelectric.com
WordPress: 4.0
Contact Form 7: 3.9.3
Am I receiving emails? = No

https://jasoncardosophotography.com
WordPress: 3.8.4
Contact Form 7: 3.9.3
Am I receiving emails? = No

https://jobmobz.com
WordPress: 4.0
Contact Form 7: 3.9.3
Am I receiving emails? = No

https://lady-code.com
WordPress: 3.8.3
Contact Form 7: 3.9.3
Am I receiving emails? = Yes

https://lbmobiletelecommanagement.com
WordPress: 3.8.4
Contact Form 7: 3.9.3
Am I receiving emails? = No

See Contact Form 7 Email Issues. There is a link at the bottom of the page to a comprehensive and detailed article which covers a wide range of email sending issues.