form submission fails

I have a webstite with 9 forms for different purposes all was working fine but suddenly all forms are failing to submit so I installed wp-smtp to fix the wordpress mailer the emails are sent correctly from wp-smtp but failing from all the forms I tried creating a form with wp-forms and it’s working fine the email in from field is the same as the one in wp-smtp configuration and I have enabled the field force from email, yet nothing seems to work