Now we get an error: anvil.email.SendFailure: Invalid Addresses (SendFailedException). You have enabled Custom SMTP for email sending - did you configure it correctly? You may need to provide a valid from_address.
I know this is an older thread, but my problem is recent and this fixes it.
I tried setting the from address as instructed above but for some reason it was not applied to the email. BTW - I upgraded to hobby to be able to set the from address. It still did not work.
Checking my email server I was getting this message:
So I went to the Custom Sign Up Flow that I had added to my dependencies and in the ServerModule1 / def _send_email_confirm_link(email): function
I modified the call to the anvil.email.send function to include a from_address header to include my server user address.
anvil.email.send(to=user['email'], subject="Confirm your email address", from_address="Jim@xyzxyz.com", text=f"""
I removed the installed dependency and reinstalled the edited dependency.