biegstal

Problem solved Sending email and FROM email must be equal.

I can send an email via WP-mail-SMTP, this works well

I’m only using the wp-mail-smtp plugin

After adding content to functions.php the website gives Error 500.
If you look at the page https://hetbrandpunt.net/nieuwsbrief-archief/ it look likes there is random added newsletters.

There is no undo (Ctrl -z) option.

The WebAPI is on, smtp.sendgrid.net is the hostname. But still the problem exists. SwiftMailer is de-installed.

Even without SwiftMailer the problem consists.