How do I keep sendgrid for emails coming from me, and use another way for a contact form? (verified user identity issue!)

I configured my rails 5.2 app to send email confirmation and others using devise and Sendgrid. It works perfectly. I am now trying to add a contact form. so the from: mail could be any one and the to: mail will be me. But now that Sendgrid requires a verified Sender Identity, it will never be able to work... I got this error: The from address does not match a verified Sender Identity.
How can I still use sendgrid for the mail I send, but use another way to get the contact form to work? What other way would you advise? Thanks a lot!