Attachment not in mail

Where can we see the website in question?

https://willedonker.nl/vacatures/werkstudent-omgevingsrecht/

See Setting up mail

What email settings do you have in the Mail tab panel?

To protect personal data, hiding email addresses in the settings or replacing them with dummy addresses is strongly advised. You can also include screenshots.

Hi Takayuki,

In this link the screenshot of the mail tab.
https://snipboard.io/DsHYfp.jpg

What other plugins and theme do you use on the site?

Hi Takayuki,

We use a custom theme and this plugins:
– Advanced Custom Fields PRO
– Classic Editor
– Contact Form 7
– EWWW Image Optimizer
– Flamingo
– MC4WP: Mailchimp for WordPress
– Regenerate Thumbnails
– Search Everything
– Simple 301 Redirects
– Simple Page Ordering
– Simple Share Buttons Adder
– Tawk.to Live Chat
– User Switching
– Wordfence Security
– WordPress Post Type Archive Links
– WP Rocket
– WPFront User Role Editor
– WPML Multilingual CMS
– WPML SEO
– WPML String Translation
– Yoast SEO

Try switching to the default theme, deactivating all plugins excluding Contact Form 7, Classic Editor, Flamingo, Wordfence Security and Yoast SEO, and clearing all cache data.

Why you are advised to deactivate plugins and switch to the default theme.

Hi Takayuki,

I’ve downgraded CF7 and the issue was ‘solved’ in version 5.4. Hopefully you’ll have a clue about what’s going wrong here..

But that’s not a fix for this problem.. I can’t downgrade CF7 because of all the security fixes in earlier versions.