I found the way to fix it. Apparently, Contact Form 7 or Sendgrid refuses to work properly if FROM and TO fields have email addresses from the same domain. I’ve changed the email address provided to the TO field to my email address on another domain and it worked out.
I guess it might be useful for those who will stumble across this topic looking for a solution.
Hey, I have the same problem. Did you find a solution?
Hey, I have the same problem here. Sendgrid blocks emails sent by Contact Form 7 for some reason. Emails sent by WP and other plugins (EDD, MyMail) are delivered without any problems. Did you find the way to make it work?